diff --git a/packages/react-native/Libraries/ActionSheetIOS/ActionSheetIOS.js b/packages/react-native/Libraries/ActionSheetIOS/ActionSheetIOS.js
index 4cb8fcf51460..bac068ea8053 100644
--- a/packages/react-native/Libraries/ActionSheetIOS/ActionSheetIOS.js
+++ b/packages/react-native/Libraries/ActionSheetIOS/ActionSheetIOS.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -49,6 +49,7 @@ export type ShareActionSheetIOSOptions = Readonly<{
 export type ShareActionSheetError = Readonly<{
   domain: string,
   code: string,
+  // $FlowFixMe[unclear-type]
   userInfo?: ?Object,
   message: string,
 }>;
@@ -155,7 +156,9 @@ const ActionSheetIOS = {
    */
   showShareActionSheetWithOptions(
     options: ShareActionSheetIOSOptions,
+    // $FlowFixMe[unclear-type]
     failureCallback: Function | ((error: ShareActionSheetError) => void),
+    // $FlowFixMe[unclear-type]
     successCallback: Function | ((success: boolean, method: ?string) => void),
   ) {
     invariant(
diff --git a/packages/react-native/Libraries/Alert/Alert.js b/packages/react-native/Libraries/Alert/Alert.js
index 4130ec511438..7d844cf63da9 100644
--- a/packages/react-native/Libraries/Alert/Alert.js
+++ b/packages/react-native/Libraries/Alert/Alert.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -26,6 +26,7 @@ export type AlertButtonStyle = 'default' | 'cancel' | 'destructive';
 
 export type AlertButton = {
   text?: string,
+  // $FlowFixMe[unclear-type]
   onPress?: ?((value?: string) => any) | ?Function,
   isPreferred?: boolean,
   style?: AlertButtonStyle,
@@ -121,6 +122,7 @@ class Alert {
         cancelable: false,
       };
 
+      // $FlowFixMe[sketchy-null-bool]
       if (options && options.cancelable) {
         config.cancelable = options.cancelable;
       }
@@ -141,6 +143,7 @@ class Alert {
         config.buttonNegative = buttonNegative.text || '';
       }
       if (buttonPositive) {
+        // $FlowFixMe[sketchy-null-string]
         config.buttonPositive = buttonPositive.text || defaultPositiveText;
       }
 
@@ -186,6 +189,7 @@ class Alert {
     options?: AlertOptions,
   ): void {
     if (Platform.OS === 'ios') {
+      // $FlowFixMe[unclear-type]
       let callbacks: Array<?any> = [];
       const buttons = [];
       let cancelButtonKey;
@@ -201,9 +205,11 @@ class Alert {
           } else if (btn.style === 'destructive') {
             destructiveButtonKey = String(index);
           }
+          // $FlowFixMe[sketchy-null-bool]
           if (btn.isPreferred) {
             preferredButtonKey = String(index);
           }
+          // $FlowFixMe[sketchy-null-string]
           if (btn.text || index < (callbackOrButtons || []).length - 1) {
             const btnDef: {[number]: string} = {};
             btnDef[index] = btn.text || '';
@@ -215,6 +221,7 @@ class Alert {
       alertWithArgs(
         {
           title: title || '',
+          // $FlowFixMe[sketchy-null-string]
           message: message || undefined,
           buttons,
           type: type || undefined,
diff --git a/packages/react-native/Libraries/Animated/AnimatedEvent.js b/packages/react-native/Libraries/Animated/AnimatedEvent.js
index 866e9bdb20d7..f8926d815d16 100644
--- a/packages/react-native/Libraries/Animated/AnimatedEvent.js
+++ b/packages/react-native/Libraries/Animated/AnimatedEvent.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -29,6 +29,7 @@ export type EventConfig<T> = {
 };
 
 export function attachNativeEventImpl(
+  // $FlowFixMe[unclear-type]
   viewRef: any,
   eventName: string,
   argMapping: ReadonlyArray<?Mapping>,
@@ -57,6 +58,7 @@ export function attachNativeEventImpl(
   };
 
   invariant(
+    // $FlowFixMe[sketchy-null-mixed]
     argMapping[0] && argMapping[0].nativeEvent,
     'Native driven events only support animated values contained inside `nativeEvent`.',
   );
@@ -91,7 +93,9 @@ export function attachNativeEventImpl(
   };
 }
 
+// $FlowFixMe[unclear-type]
 function validateMapping(argMapping: ReadonlyArray<?Mapping>, args: any) {
+  // $FlowFixMe[unclear-type]
   const validate = (recMapping: ?Mapping, recEvt: any, key: string) => {
     if (recMapping instanceof AnimatedValue) {
       invariant(
@@ -145,16 +149,19 @@ function validateMapping(argMapping: ReadonlyArray<?Mapping>, args: any) {
 
 export class AnimatedEvent {
   _argMapping: ReadonlyArray<?Mapping>;
+  // $FlowFixMe[unclear-type]
   _listeners: Array<Function> = [];
   _attachedEvent: ?{detach: () => void, ...};
   __isNative: boolean;
   __platformConfig: ?PlatformConfig;
 
+  // $FlowFixMe[unclear-type]
   constructor(argMapping: ReadonlyArray<?Mapping>, config: EventConfig<any>) {
     this._argMapping = argMapping;
 
     if (config == null) {
       console.warn('Animated.event now requires a second argument for options');
+      // $FlowFixMe[reassign-const]
       config = {useNativeDriver: false};
     }
 
@@ -166,14 +173,17 @@ export class AnimatedEvent {
     this.__platformConfig = config.platformConfig;
   }
 
+  // $FlowFixMe[unclear-type]
   __addListener(callback: Function): void {
     this._listeners.push(callback);
   }
 
+  // $FlowFixMe[unclear-type]
   __removeListener(callback: Function): void {
     this._listeners = this._listeners.filter(listener => listener !== callback);
   }
 
+  // $FlowFixMe[unclear-type]
   __attach(viewRef: any, eventName: string): void {
     invariant(
       this.__isNative,
@@ -188,6 +198,7 @@ export class AnimatedEvent {
     );
   }
 
+  // $FlowFixMe[unclear-type]
   __detach(viewTag: any, eventName: string): void {
     invariant(
       this.__isNative,
@@ -197,10 +208,12 @@ export class AnimatedEvent {
     this._attachedEvent && this._attachedEvent.detach();
   }
 
+  // $FlowFixMe[unclear-type]
   __getHandler(): any | ((...args: any) => void) {
     if (this.__isNative) {
       if (__DEV__) {
         let validatedMapping = false;
+        // $FlowFixMe[unclear-type]
         return (...args: any) => {
           if (!validatedMapping) {
             validateMapping(this._argMapping, args);
@@ -214,6 +227,7 @@ export class AnimatedEvent {
     }
 
     let validatedMapping = false;
+    // $FlowFixMe[unclear-type]
     return (...args: any) => {
       if (__DEV__ && !validatedMapping) {
         validateMapping(this._argMapping, args);
@@ -222,6 +236,7 @@ export class AnimatedEvent {
 
       const traverse = (
         recMapping: ?(Mapping | AnimatedValue),
+        // $FlowFixMe[unclear-type]
         recEvt: any,
       ) => {
         if (recMapping instanceof AnimatedValue) {
@@ -250,6 +265,7 @@ export class AnimatedEvent {
     };
   }
 
+  // $FlowFixMe[unclear-type]
   _callListeners = (...args: any) => {
     this._listeners.forEach(listener => listener(...args));
   };
diff --git a/packages/react-native/Libraries/Animated/AnimatedExports.js b/packages/react-native/Libraries/Animated/AnimatedExports.js
index 55940d81c39e..4cb32cf74e00 100644
--- a/packages/react-native/Libraries/Animated/AnimatedExports.js
+++ b/packages/react-native/Libraries/Animated/AnimatedExports.js
@@ -4,10 +4,12 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
+// flowlint unsafe-getters-setters:off
+
 import typeof AnimatedFlatList from './components/AnimatedFlatList';
 import typeof AnimatedImage from './components/AnimatedImage';
 import typeof AnimatedScrollView from './components/AnimatedScrollView';
@@ -27,7 +29,7 @@ export default {
   /**
    * FlatList and SectionList infer generic Type defined under their `data` and `section` props.
    */
-  get FlatList(): AnimatedFlatList<any> {
+  get FlatList(): AnimatedFlatList<> {
     return require('./components/AnimatedFlatList').default;
   },
   /**
@@ -47,7 +49,7 @@ export default {
   /**
    * FlatList and SectionList infer generic Type defined under their `data` and `section` props.
    */
-  get SectionList(): AnimatedSectionList<any, any> {
+  get SectionList(): AnimatedSectionList<> {
     return require('./components/AnimatedSectionList').default;
   },
   /**
diff --git a/packages/react-native/Libraries/Animated/AnimatedExports.js.flow b/packages/react-native/Libraries/Animated/AnimatedExports.js.flow
index 7880f98f97af..6178617cec5b 100644
--- a/packages/react-native/Libraries/Animated/AnimatedExports.js.flow
+++ b/packages/react-native/Libraries/Animated/AnimatedExports.js.flow
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
diff --git a/packages/react-native/Libraries/Animated/AnimatedImplementation.js b/packages/react-native/Libraries/Animated/AnimatedImplementation.js
index 4a9d76a4806a..0b462419e380 100644
--- a/packages/react-native/Libraries/Animated/AnimatedImplementation.js
+++ b/packages/react-native/Libraries/Animated/AnimatedImplementation.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -127,7 +127,9 @@ const _combineCallbacks = function (
 
 const maybeVectorAnim = function (
   value: AnimatedValue | AnimatedValueXY | AnimatedColor,
+  // $FlowFixMe[unclear-type]
   config: Object,
+  // $FlowFixMe[unclear-type]
   anim: (value: AnimatedValue, config: Object) => CompositeAnimation,
 ): ?CompositeAnimation {
   if (value instanceof AnimatedValueXY) {
@@ -184,8 +186,11 @@ const springImpl = function (
     configuration: SpringAnimationConfig,
     callback?: ?EndCallback,
   ): void {
+    // $FlowFixMe[reassign-const]
     callback = _combineCallbacks(callback, configuration);
+    // $FlowFixMe[unclear-type]
     const singleValue: any = animatedValue;
+    // $FlowFixMe[unclear-type]
     const singleConfig: any = configuration;
     singleValue.stopTracking();
     if (configuration.toValue instanceof AnimatedNode) {
@@ -241,8 +246,11 @@ const timingImpl = function (
     configuration: TimingAnimationConfig,
     callback?: ?EndCallback,
   ): void {
+    // $FlowFixMe[reassign-const]
     callback = _combineCallbacks(callback, configuration);
+    // $FlowFixMe[unclear-type]
     const singleValue: any = animatedValue;
+    // $FlowFixMe[unclear-type]
     const singleConfig: any = configuration;
     singleValue.stopTracking();
     if (configuration.toValue instanceof AnimatedNode) {
@@ -299,8 +307,11 @@ const decayImpl = function (
     configuration: DecayAnimationConfig,
     callback?: ?EndCallback,
   ): void {
+    // $FlowFixMe[reassign-const]
     callback = _combineCallbacks(callback, configuration);
+    // $FlowFixMe[unclear-type]
     const singleValue: any = animatedValue;
+    // $FlowFixMe[unclear-type]
     const singleConfig: any = configuration;
     singleValue.stopTracking();
     singleValue.animate(new DecayAnimation(singleConfig), callback);
@@ -551,8 +562,11 @@ const loopImpl = function (
 };
 
 function forkEventImpl(
+  // $FlowFixMe[unclear-type]
   event: ?AnimatedEvent | ?Function,
+  // $FlowFixMe[unclear-type]
   listener: Function,
+  // $FlowFixMe[unclear-type]
 ): AnimatedEvent | Function {
   if (!event) {
     return listener;
@@ -568,7 +582,9 @@ function forkEventImpl(
 }
 
 function unforkEventImpl(
+  // $FlowFixMe[unclear-type]
   event: ?AnimatedEvent | ?Function,
+  // $FlowFixMe[unclear-type]
   listener: Function,
 ): void {
   if (event && event instanceof AnimatedEvent) {
@@ -579,6 +595,7 @@ function unforkEventImpl(
 const eventImpl = function <T>(
   argMapping: ReadonlyArray<?Mapping>,
   config: EventConfig<T>,
+  // $FlowFixMe[unclear-type]
 ): any {
   const animatedEvent = new AnimatedEvent(argMapping, config);
   if (animatedEvent.__isNative) {
diff --git a/packages/react-native/Libraries/Animated/AnimatedMock.js b/packages/react-native/Libraries/Animated/AnimatedMock.js
index 88eab8815388..dee70ba1a01a 100644
--- a/packages/react-native/Libraries/Animated/AnimatedMock.js
+++ b/packages/react-native/Libraries/Animated/AnimatedMock.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -94,6 +94,7 @@ const spring = function (
   value: AnimatedValue | AnimatedValueXY | AnimatedColor,
   config: SpringAnimationConfig,
 ): CompositeAnimation {
+  // $FlowFixMe[unclear-type]
   const anyValue: any = value;
   return {
     ...emptyAnimation,
@@ -108,6 +109,7 @@ const timing = function (
   value: AnimatedValue | AnimatedValueXY | AnimatedColor,
   config: TimingAnimationConfig,
 ): CompositeAnimation {
+  // $FlowFixMe[unclear-type]
   const anyValue: any = value;
   return {
     ...emptyAnimation,
diff --git a/packages/react-native/Libraries/Animated/createAnimatedComponent.js b/packages/react-native/Libraries/Animated/createAnimatedComponent.js
index 922e95ec9f6c..0c1385c52417 100644
--- a/packages/react-native/Libraries/Animated/createAnimatedComponent.js
+++ b/packages/react-native/Libraries/Animated/createAnimatedComponent.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -64,10 +64,10 @@ type PassThroughProps = Readonly<{
   passthroughAnimatedPropExplicitValues?: ViewProps | null,
 }>;
 
-type LooseOmit<O extends interface {}, K extends keyof $FlowFixMe> = Pick<
-  O,
-  Exclude<keyof O, K>,
->;
+type LooseOmit<
+  O extends interface {},
+  K extends string | number | symbol,
+> = Pick<O, Exclude<keyof O, K>>;
 
 export type AnimatedProps<Props extends {...}> = LooseOmit<
   {
@@ -94,7 +94,7 @@ export type AnimatedComponentType<
 > = component(ref?: React.RefSetter<Instance>, ...AnimatedProps<Props>);
 
 export default function createAnimatedComponent<
-  TInstance extends React.ComponentType<any>,
+  TInstance extends React.ComponentType<empty>,
 >(
   Component: TInstance,
 ): AnimatedComponentType<
@@ -158,7 +158,9 @@ export function unstable_createAnimatedComponentWithAllowlist<
   };
 
   AnimatedComponent.displayName = `Animated(${
-    Component.displayName || 'Anonymous'
+    Component.displayName != null && Component.displayName !== ''
+      ? Component.displayName
+      : 'Anonymous'
   })`;
 
   return AnimatedComponent;
diff --git a/packages/react-native/Libraries/Animated/nodes/AnimatedAddition.js b/packages/react-native/Libraries/Animated/nodes/AnimatedAddition.js
index 91d686f5af3d..0f48c8072cfe 100644
--- a/packages/react-native/Libraries/Animated/nodes/AnimatedAddition.js
+++ b/packages/react-native/Libraries/Animated/nodes/AnimatedAddition.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -61,7 +61,11 @@ export default class AnimatedAddition extends AnimatedWithChildren {
     super.__detach();
   }
 
-  __getNativeConfig(): any {
+  __getNativeConfig(): {
+    type: string,
+    input: [number, number],
+    debugID: ?string,
+  } {
     return {
       type: 'addition',
       input: [this._a.__getNativeTag(), this._b.__getNativeTag()],
diff --git a/packages/react-native/Libraries/Animated/nodes/AnimatedColor.js b/packages/react-native/Libraries/Animated/nodes/AnimatedColor.js
index 712c259d72ca..252814fd071d 100644
--- a/packages/react-native/Libraries/Animated/nodes/AnimatedColor.js
+++ b/packages/react-native/Libraries/Animated/nodes/AnimatedColor.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -90,9 +90,10 @@ function processColor(
   return null;
 }
 
-function isRgbaValue(value: any): boolean {
+function isRgbaValue(value: unknown): boolean {
   return (
-    value &&
+    value != null &&
+    typeof value === 'object' &&
     typeof value.r === 'number' &&
     typeof value.g === 'number' &&
     typeof value.b === 'number' &&
@@ -100,9 +101,10 @@ function isRgbaValue(value: any): boolean {
   );
 }
 
-function isRgbaAnimatedValue(value: any): boolean {
+function isRgbaAnimatedValue(value: unknown): boolean {
   return (
-    value &&
+    value != null &&
+    typeof value === 'object' &&
     value.r instanceof AnimatedValue &&
     value.g instanceof AnimatedValue &&
     value.b instanceof AnimatedValue &&
@@ -166,7 +168,7 @@ export default class AnimatedColor extends AnimatedWithChildren {
       this.a = new AnimatedValue(initColor.a);
     }
 
-    if (config?.useNativeDriver) {
+    if (config?.useNativeDriver === true) {
       this.__makeNative();
     }
   }
@@ -325,7 +327,15 @@ export default class AnimatedColor extends AnimatedWithChildren {
     super.__makeNative(platformConfig);
   }
 
-  __getNativeConfig(): {...} {
+  __getNativeConfig(): {
+    type: string,
+    r: number,
+    g: number,
+    b: number,
+    a: number,
+    nativeColor: ?NativeColorValue,
+    debugID: ?string,
+  } {
     return {
       type: 'color',
       r: this.r.__getNativeTag(),
diff --git a/packages/react-native/Libraries/Animated/nodes/AnimatedDiffClamp.js b/packages/react-native/Libraries/Animated/nodes/AnimatedDiffClamp.js
index 94fef85aa0e1..29d0d170ad5c 100644
--- a/packages/react-native/Libraries/Animated/nodes/AnimatedDiffClamp.js
+++ b/packages/react-native/Libraries/Animated/nodes/AnimatedDiffClamp.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -68,7 +68,13 @@ export default class AnimatedDiffClamp extends AnimatedWithChildren {
     super.__detach();
   }
 
-  __getNativeConfig(): any {
+  __getNativeConfig(): {
+    type: string,
+    input: number,
+    min: number,
+    max: number,
+    debugID: ?string,
+  } {
     return {
       type: 'diffclamp',
       input: this._a.__getNativeTag(),
diff --git a/packages/react-native/Libraries/Animated/nodes/AnimatedDivision.js b/packages/react-native/Libraries/Animated/nodes/AnimatedDivision.js
index 6b73ff7d9931..ac8eba488ecf 100644
--- a/packages/react-native/Libraries/Animated/nodes/AnimatedDivision.js
+++ b/packages/react-native/Libraries/Animated/nodes/AnimatedDivision.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -77,7 +77,11 @@ export default class AnimatedDivision extends AnimatedWithChildren {
     super.__detach();
   }
 
-  __getNativeConfig(): any {
+  __getNativeConfig(): {
+    type: string,
+    input: [number, number],
+    debugID: ?string,
+  } {
     return {
       type: 'division',
       input: [this._a.__getNativeTag(), this._b.__getNativeTag()],
diff --git a/packages/react-native/Libraries/Animated/nodes/AnimatedInterpolation.js b/packages/react-native/Libraries/Animated/nodes/AnimatedInterpolation.js
index b6a0d4d3b5f5..2de142791f13 100644
--- a/packages/react-native/Libraries/Animated/nodes/AnimatedInterpolation.js
+++ b/packages/react-native/Libraries/Animated/nodes/AnimatedInterpolation.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -49,7 +49,7 @@ export type InterpolationConfigType<
 function createNumericInterpolation(
   config: InterpolationConfigType<number>,
 ): (input: number) => number {
-  const outputRange: ReadonlyArray<number> = config.outputRange as any;
+  const outputRange: ReadonlyArray<number> = config.outputRange;
   const inputRange = config.inputRange;
 
   const easing = config.easing || Easing.linear;
@@ -84,6 +84,7 @@ function createNumericInterpolation(
       easing,
       extrapolateLeft,
       extrapolateRight,
+      // $FlowFixMe[unclear-type]
     ) as any;
   };
 }
@@ -203,6 +204,7 @@ function mapStringToNumericComponents(
     const components: Array<string | number> = [];
     let lastMatchEnd = 0;
     let match: RegExp$matchResult;
+    // $FlowFixMe[unclear-type]
     while ((match = numericComponentRegex.exec(input) as any) != null) {
       if (match.index > lastMatchEnd) {
         components.push(input.substring(lastMatchEnd, match.index));
@@ -466,12 +468,16 @@ export default class AnimatedInterpolation<
     if (!this._interpolation) {
       const config = this._config;
       if (config.outputRange && typeof config.outputRange[0] === 'string') {
+        // $FlowFixMe[unclear-type]
         this._interpolation = createStringInterpolation(config as any) as any;
       } else if (typeof config.outputRange[0] === 'object') {
         this._interpolation = createPlatformColorInterpolation(
+          // $FlowFixMe[unclear-type]
           config as any,
+          // $FlowFixMe[unclear-type]
         ) as any;
       } else {
+        // $FlowFixMe[unclear-type]
         this._interpolation = createNumericInterpolation(config as any) as any;
       }
     }
@@ -508,6 +514,7 @@ export default class AnimatedInterpolation<
     super.__detach();
   }
 
+  // $FlowFixMe[unclear-type]
   __getNativeConfig(): any {
     if (__DEV__) {
       validateInterpolation(this._config);
@@ -526,6 +533,7 @@ export default class AnimatedInterpolation<
         } else {
           return NativeAnimatedHelper.transformDataType(value);
         }
+        // $FlowFixMe[unclear-type]
       }) as any;
     } else if (typeof outputRange[0] === 'object') {
       outputType = 'platform_color';
diff --git a/packages/react-native/Libraries/Animated/nodes/AnimatedModulo.js b/packages/react-native/Libraries/Animated/nodes/AnimatedModulo.js
index 32a698afbdac..91825c3dcf0f 100644
--- a/packages/react-native/Libraries/Animated/nodes/AnimatedModulo.js
+++ b/packages/react-native/Libraries/Animated/nodes/AnimatedModulo.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -55,7 +55,12 @@ export default class AnimatedModulo extends AnimatedWithChildren {
     super.__detach();
   }
 
-  __getNativeConfig(): any {
+  __getNativeConfig(): {
+    type: string,
+    input: number,
+    modulus: number,
+    debugID: ?string,
+  } {
     return {
       type: 'modulus',
       input: this._a.__getNativeTag(),
diff --git a/packages/react-native/Libraries/Animated/nodes/AnimatedMultiplication.js b/packages/react-native/Libraries/Animated/nodes/AnimatedMultiplication.js
index 93764f86c751..0411cb593ad3 100644
--- a/packages/react-native/Libraries/Animated/nodes/AnimatedMultiplication.js
+++ b/packages/react-native/Libraries/Animated/nodes/AnimatedMultiplication.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -60,7 +60,11 @@ export default class AnimatedMultiplication extends AnimatedWithChildren {
     super.__detach();
   }
 
-  __getNativeConfig(): any {
+  __getNativeConfig(): {
+    type: string,
+    input: [number, number],
+    debugID: ?string,
+  } {
     return {
       type: 'multiplication',
       input: [this._a.__getNativeTag(), this._b.__getNativeTag()],
diff --git a/packages/react-native/Libraries/Animated/nodes/AnimatedNode.js b/packages/react-native/Libraries/Animated/nodes/AnimatedNode.js
index b10fe9da8bee..5eb2d18b2865 100644
--- a/packages/react-native/Libraries/Animated/nodes/AnimatedNode.js
+++ b/packages/react-native/Libraries/Animated/nodes/AnimatedNode.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -55,7 +55,9 @@ export default class AnimatedNode {
       this.__nativeTag = undefined;
     }
   }
+  // $FlowFixMe[unclear-type]
   __getValue(): any {}
+  // $FlowFixMe[unclear-type]
   __getAnimatedValue(): any {
     return this.__getValue();
   }
@@ -87,6 +89,7 @@ export default class AnimatedNode {
    *
    * See https://reactnative.dev/docs/animatedvalue#addlistener
    */
+  // $FlowFixMe[unclear-type]
   addListener(callback: (value: any) => unknown): string {
     const id = String(_uniqueId++);
     this._listeners.set(id, callback);
@@ -146,6 +149,7 @@ export default class AnimatedNode {
       if (this._platformConfig) {
         config.platformConfig = this._platformConfig;
       }
+      // $FlowFixMe[sketchy-null-bool]
       if (this.__disableBatchingForNativeCreate) {
         config.disableBatchingForNativeCreate = true;
       }
@@ -154,6 +158,7 @@ export default class AnimatedNode {
     return nativeTag;
   }
 
+  // $FlowFixMe[unclear-type]
   __getNativeConfig(): Object {
     throw new Error(
       'This JS animated node type cannot be used as native animated node',
diff --git a/packages/react-native/Libraries/Animated/nodes/AnimatedObject.js b/packages/react-native/Libraries/Animated/nodes/AnimatedObject.js
index 8f1793ec0472..6cbae410ddc1 100644
--- a/packages/react-native/Libraries/Animated/nodes/AnimatedObject.js
+++ b/packages/react-native/Libraries/Animated/nodes/AnimatedObject.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -64,7 +64,11 @@ function flatAnimatedNodes(
 }
 
 // Returns a copy of value with a transformation fn applied to any AnimatedNodes
-function mapAnimatedNodes(value: any, fn: any => any, depth: number = 0): any {
+function mapAnimatedNodes(
+  value: unknown,
+  fn: (node: AnimatedNode) => unknown,
+  depth: number = 0,
+): unknown {
   if (depth >= MAX_DEPTH) {
     return value;
   }
@@ -74,7 +78,7 @@ function mapAnimatedNodes(value: any, fn: any => any, depth: number = 0): any {
   } else if (Array.isArray(value)) {
     return value.map(element => mapAnimatedNodes(element, fn, depth + 1));
   } else if (isPlainObject(value)) {
-    const result: {[string]: any} = {};
+    const result: {[string]: unknown} = {};
     const keys = Object.keys(value);
     for (let ii = 0, length = keys.length; ii < length; ii++) {
       const key = keys[ii];
@@ -115,13 +119,13 @@ export default class AnimatedObject extends AnimatedWithChildren {
     this._value = value;
   }
 
-  __getValue(): any {
+  __getValue(): unknown {
     return mapAnimatedNodes(this._value, node => {
       return node.__getValue();
     });
   }
 
-  __getValueWithStaticObject(staticObject: unknown): any {
+  __getValueWithStaticObject(staticObject: unknown): unknown {
     const nodes = this._nodes;
     let index = 0;
     // NOTE: We can depend on `this._value` and `staticObject` sharing a
@@ -129,7 +133,7 @@ export default class AnimatedObject extends AnimatedWithChildren {
     return mapAnimatedNodes(staticObject, () => nodes[index++].__getValue());
   }
 
-  __getAnimatedValue(): any {
+  __getAnimatedValue(): unknown {
     return mapAnimatedNodes(this._value, node => {
       return node.__getAnimatedValue();
     });
@@ -162,7 +166,11 @@ export default class AnimatedObject extends AnimatedWithChildren {
     super.__makeNative(platformConfig);
   }
 
-  __getNativeConfig(): any {
+  __getNativeConfig(): {
+    type: string,
+    value: unknown,
+    debugID: ?string,
+  } {
     return {
       type: 'object',
       value: mapAnimatedNodes(this._value, node => {
diff --git a/packages/react-native/Libraries/Animated/nodes/AnimatedProps.js b/packages/react-native/Libraries/Animated/nodes/AnimatedProps.js
index 6581c150f437..fcc1661d4dea 100644
--- a/packages/react-native/Libraries/Animated/nodes/AnimatedProps.js
+++ b/packages/react-native/Libraries/Animated/nodes/AnimatedProps.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -119,6 +119,7 @@ export default class AnimatedProps extends AnimatedNode {
     this._rootTag = rootTag;
   }
 
+  // $FlowFixMe[unclear-type]
   __getValue(): Object {
     const props: {[string]: unknown} = {};
 
@@ -144,6 +145,7 @@ export default class AnimatedProps extends AnimatedNode {
    * `staticProps` object, except with animated nodes for any props that were
    * created by this `AnimatedProps` instance.
    */
+  // $FlowFixMe[unclear-type]
   __getValueWithStaticProps(staticProps: Object): Object {
     const props: {[string]: unknown} = {...staticProps};
 
@@ -196,6 +198,7 @@ export default class AnimatedProps extends AnimatedNode {
     return tuples;
   }
 
+  // $FlowFixMe[unclear-type]
   __getAnimatedValue(): Object {
     const props: {[string]: unknown} = {};
 
@@ -356,6 +359,7 @@ export default class AnimatedProps extends AnimatedNode {
     }
   }
 
+  // $FlowFixMe[unclear-type]
   __getNativeConfig(): Object {
     const platformConfig = this.__getPlatformConfig();
     const propsConfig: {[string]: number} = {};
diff --git a/packages/react-native/Libraries/Animated/nodes/AnimatedStyle.js b/packages/react-native/Libraries/Animated/nodes/AnimatedStyle.js
index 3b04b8ba2835..57a9fc816153 100644
--- a/packages/react-native/Libraries/Animated/nodes/AnimatedStyle.js
+++ b/packages/react-native/Libraries/Animated/nodes/AnimatedStyle.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -184,6 +184,7 @@ export default class AnimatedStyle extends AnimatedWithChildren {
     }
   }
 
+  // $FlowFixMe[unclear-type]
   __getAnimatedValue(): Object {
     const style: {[string]: unknown} = {};
 
@@ -225,6 +226,7 @@ export default class AnimatedStyle extends AnimatedWithChildren {
     super.__makeNative(platformConfig);
   }
 
+  // $FlowFixMe[unclear-type]
   __getNativeConfig(): Object {
     const platformConfig = this.__getPlatformConfig();
     const styleConfig: {[string]: ?number} = {};
diff --git a/packages/react-native/Libraries/Animated/nodes/AnimatedSubtraction.js b/packages/react-native/Libraries/Animated/nodes/AnimatedSubtraction.js
index 04181bda7b20..0b1d3f22c52c 100644
--- a/packages/react-native/Libraries/Animated/nodes/AnimatedSubtraction.js
+++ b/packages/react-native/Libraries/Animated/nodes/AnimatedSubtraction.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -61,7 +61,11 @@ export default class AnimatedSubtraction extends AnimatedWithChildren {
     super.__detach();
   }
 
-  __getNativeConfig(): any {
+  __getNativeConfig(): {
+    type: string,
+    input: [number, number],
+    debugID: ?string,
+  } {
     return {
       type: 'subtraction',
       input: [this._a.__getNativeTag(), this._b.__getNativeTag()],
diff --git a/packages/react-native/Libraries/Animated/nodes/AnimatedTracking.js b/packages/react-native/Libraries/Animated/nodes/AnimatedTracking.js
index d50d2921e5b0..17229e30b3bb 100644
--- a/packages/react-native/Libraries/Animated/nodes/AnimatedTracking.js
+++ b/packages/react-native/Libraries/Animated/nodes/AnimatedTracking.js
@@ -4,33 +4,40 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
 'use strict';
 
 import type {PlatformConfig} from '../AnimatedPlatformConfig';
-import type {EndCallback} from '../animations/Animation';
+import type Animation from '../animations/Animation';
+import type {AnimationConfig, EndCallback} from '../animations/Animation';
 import type {AnimatedNodeConfig} from './AnimatedNode';
 import type AnimatedValue from './AnimatedValue';
 
 import NativeAnimatedHelper from '../../../src/private/animated/NativeAnimatedHelper';
 import AnimatedNode from './AnimatedNode';
 
+type TrackingAnimationConfig = Readonly<{
+  ...AnimationConfig,
+  toValue: AnimatedNode,
+  ...
+}>;
+
 export default class AnimatedTracking extends AnimatedNode {
   _value: AnimatedValue;
   _parent: AnimatedNode;
   _callback: ?EndCallback;
-  _animationConfig: Object;
-  _animationClass: any;
+  _animationConfig: TrackingAnimationConfig;
+  _animationClass: Class<Animation>;
   _useNativeDriver: boolean;
 
   constructor(
     value: AnimatedValue,
     parent: AnimatedNode,
-    animationClass: any,
-    animationConfig: Object,
+    animationClass: Class<Animation>,
+    animationConfig: TrackingAnimationConfig,
     callback?: ?EndCallback,
     config?: ?AnimatedNodeConfig,
   ) {
@@ -52,7 +59,7 @@ export default class AnimatedTracking extends AnimatedNode {
     this._value.__makeNative(platformConfig);
   }
 
-  __getValue(): Object {
+  __getValue(): number {
     return this._parent.__getValue();
   }
 
@@ -79,13 +86,20 @@ export default class AnimatedTracking extends AnimatedNode {
     this._value.animate(
       new this._animationClass({
         ...this._animationConfig,
-        toValue: (this._animationConfig.toValue as any).__getValue(),
+        toValue: this._animationConfig.toValue.__getValue(),
       }),
       this._callback,
     );
   }
 
-  __getNativeConfig(): any {
+  __getNativeConfig(): {
+    type: string,
+    animationId: number,
+    animationConfig: Readonly<{platformConfig: ?PlatformConfig, ...}>,
+    toValue: number,
+    value: number,
+    debugID: ?string,
+  } {
     const animation = new this._animationClass({
       ...this._animationConfig,
       // remove toValue from the config as it's a ref to Animated.Value
diff --git a/packages/react-native/Libraries/Animated/nodes/AnimatedTransform.js b/packages/react-native/Libraries/Animated/nodes/AnimatedTransform.js
index 86900cc17f84..46d9ae1f5657 100644
--- a/packages/react-native/Libraries/Animated/nodes/AnimatedTransform.js
+++ b/packages/react-native/Libraries/Animated/nodes/AnimatedTransform.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -87,6 +87,7 @@ export default class AnimatedTransform extends AnimatedWithChildren {
     super.__makeNative(platformConfig);
   }
 
+  // $FlowFixMe[unclear-type]
   __getValue(): ReadonlyArray<Transform<any>> {
     return mapTransforms(this._transforms, animatedNode =>
       animatedNode.__getValue(),
@@ -94,7 +95,9 @@ export default class AnimatedTransform extends AnimatedWithChildren {
   }
 
   __getValueWithStaticTransforms(
+    // $FlowFixMe[unclear-type]
     staticTransforms: ReadonlyArray<Object>,
+    // $FlowFixMe[unclear-type]
   ): ReadonlyArray<Object> {
     const values = [];
     mapTransforms(this._transforms, node => {
@@ -105,6 +108,7 @@ export default class AnimatedTransform extends AnimatedWithChildren {
     return mapTransforms(staticTransforms, () => values.shift());
   }
 
+  // $FlowFixMe[unclear-type]
   __getAnimatedValue(): ReadonlyArray<Transform<any>> {
     return mapTransforms(this._transforms, animatedNode =>
       animatedNode.__getAnimatedValue(),
@@ -129,7 +133,9 @@ export default class AnimatedTransform extends AnimatedWithChildren {
     super.__detach();
   }
 
+  // $FlowFixMe[unclear-type]
   __getNativeConfig(): any {
+    // $FlowFixMe[unclear-type]
     const transformsConfig: Array<any> = [];
 
     const transforms = this._transforms;
diff --git a/packages/react-native/Libraries/Animated/nodes/AnimatedValue.js b/packages/react-native/Libraries/Animated/nodes/AnimatedValue.js
index 76dba2196f48..800f8dba0350 100644
--- a/packages/react-native/Libraries/Animated/nodes/AnimatedValue.js
+++ b/packages/react-native/Libraries/Animated/nodes/AnimatedValue.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -55,10 +55,12 @@ const NativeAnimatedAPI = NativeAnimatedHelper.API;
  * transform which can receive values from multiple parents.
  */
 export function flushValue(rootNode: AnimatedNode): void {
-  const leaves = new Set<{update: () => void, ...}>();
+  const leaves = new Set<interface {update: () => void}>();
   function findAnimatedStyles(node: AnimatedNode) {
-    // $FlowFixMe[prop-missing]
-    if (typeof node.update === 'function') {
+    if (
+      typeof (node as interface {update?: () => void}).update === 'function'
+    ) {
+      // $FlowFixMe[unclear-type] `update` is duck-typed on animated leaf nodes and not declared on AnimatedNode
       leaves.add(node as any);
     } else {
       node.__getChildren().forEach(findAnimatedStyles);
@@ -138,7 +140,7 @@ export default class AnimatedValue extends AnimatedWithChildren {
     }
   }
 
-  addListener(callback: (value: any) => unknown): string {
+  addListener(callback: (value: {value: number}) => unknown): string {
     const id = super.addListener(callback);
     this._listenerCount++;
     if (this.__isNative) {
@@ -371,7 +373,12 @@ export default class AnimatedValue extends AnimatedWithChildren {
     this.__callListeners(this.__getValue());
   }
 
-  __getNativeConfig(): Object {
+  __getNativeConfig(): {
+    type: string,
+    value: number,
+    offset: number,
+    debugID: ?string,
+  } {
     return {
       type: 'value',
       value: this._value,
diff --git a/packages/react-native/Libraries/Animated/nodes/AnimatedValueXY.js b/packages/react-native/Libraries/Animated/nodes/AnimatedValueXY.js
index 0c008919c8b8..a2634798a856 100644
--- a/packages/react-native/Libraries/Animated/nodes/AnimatedValueXY.js
+++ b/packages/react-native/Libraries/Animated/nodes/AnimatedValueXY.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -52,18 +52,23 @@ export default class AnimatedValueXY extends AnimatedWithChildren {
     config?: ?AnimatedValueXYConfig,
   ) {
     super(config);
-    const value: any = valueIn || {x: 0, y: 0}; // @flowfixme: shouldn't need `: any`
-    if (typeof value.x === 'number' && typeof value.y === 'number') {
-      this.x = new AnimatedValue(value.x);
-      this.y = new AnimatedValue(value.y);
+    const value: {
+      readonly x: number | AnimatedValue,
+      readonly y: number | AnimatedValue,
+      ...
+    } = valueIn || {x: 0, y: 0};
+    const {x, y} = value;
+    if (typeof x === 'number' && typeof y === 'number') {
+      this.x = new AnimatedValue(x);
+      this.y = new AnimatedValue(y);
     } else {
       invariant(
-        value.x instanceof AnimatedValue && value.y instanceof AnimatedValue,
+        x instanceof AnimatedValue && y instanceof AnimatedValue,
         'AnimatedValueXY must be initialized with an object of numbers or ' +
           'AnimatedValues.',
       );
-      this.x = value.x;
-      this.y = value.y;
+      this.x = x;
+      this.y = y;
     }
     this._listeners = {};
     if (config && config.useNativeDriver) {
@@ -164,7 +169,7 @@ export default class AnimatedValueXY extends AnimatedWithChildren {
    */
   addListener(callback: ValueXYListenerCallback): string {
     const id = String(_uniqueId++);
-    const jointCallback = ({value: number}: any) => {
+    const jointCallback = () => {
       callback(this.__getValue());
     };
     this._listeners[id] = {
diff --git a/packages/react-native/Libraries/Blob/File.js b/packages/react-native/Libraries/Blob/File.js
index 0783d1c503b6..ccbd83dba703 100644
--- a/packages/react-native/Libraries/Blob/File.js
+++ b/packages/react-native/Libraries/Blob/File.js
@@ -4,10 +4,12 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
+// flowlint unsafe-getters-setters:off
+
 'use strict';
 
 import type {BlobOptions} from './BlobTypes';
diff --git a/packages/react-native/Libraries/Blob/FileReader.js b/packages/react-native/Libraries/Blob/FileReader.js
index 3745c00923a8..c566a765c100 100644
--- a/packages/react-native/Libraries/Blob/FileReader.js
+++ b/packages/react-native/Libraries/Blob/FileReader.js
@@ -4,10 +4,12 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
+// flowlint unsafe-getters-setters:off
+
 import type {EventCallback} from '../../src/private/webapis/dom/events/EventTarget';
 import type Blob from './Blob';
 
diff --git a/packages/react-native/Libraries/Blob/URL.js b/packages/react-native/Libraries/Blob/URL.js
index f4f879a51214..8386cc6d979d 100644
--- a/packages/react-native/Libraries/Blob/URL.js
+++ b/packages/react-native/Libraries/Blob/URL.js
@@ -4,10 +4,12 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
+// flowlint unsafe-getters-setters:off
+
 import type Blob from './Blob';
 
 import NativeBlobModule from './NativeBlobModule';
@@ -79,7 +81,7 @@ export class URL {
   // $FlowFixMe[missing-local-annot]
   constructor(url: string, base?: string | URL) {
     let baseUrl = null;
-    if (!base || validateBaseUrl(url)) {
+    if (base == null || base === '' || validateBaseUrl(url)) {
       this._url = url;
       if (this._url.includes('#')) {
         const split = this._url.split('#');
@@ -112,13 +114,14 @@ export class URL {
       if (baseUrl.endsWith('/')) {
         baseUrl = baseUrl.slice(0, baseUrl.length - 1);
       }
-      if (!url.startsWith('/')) {
-        url = `/${url}`;
+      let path = url;
+      if (!path.startsWith('/')) {
+        path = `/${path}`;
       }
-      if (baseUrl.endsWith(url)) {
-        url = '';
+      if (baseUrl.endsWith(path)) {
+        path = '';
       }
-      this._url = `${baseUrl}${url}`;
+      this._url = `${baseUrl}${path}`;
     }
   }
 
diff --git a/packages/react-native/Libraries/Blob/URLSearchParams.js b/packages/react-native/Libraries/Blob/URLSearchParams.js
index d325f7bb25a8..1cf3ef6b2f4e 100644
--- a/packages/react-native/Libraries/Blob/URLSearchParams.js
+++ b/packages/react-native/Libraries/Blob/URLSearchParams.js
@@ -4,10 +4,12 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
+// flowlint unsafe-getters-setters:off
+
 // Small subset from whatwg-url: https://github.com/jsdom/whatwg-url/tree/master/src
 // The reference code bloat comes from Unicode issues with URLs, so those won't work here.
 export class URLSearchParams {
diff --git a/packages/react-native/Libraries/Blob/URLSearchParams.js.flow b/packages/react-native/Libraries/Blob/URLSearchParams.js.flow
index df5b32557dda..fe7741a88d41 100644
--- a/packages/react-native/Libraries/Blob/URLSearchParams.js.flow
+++ b/packages/react-native/Libraries/Blob/URLSearchParams.js.flow
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
diff --git a/packages/react-native/Libraries/Components/ActivityIndicator/ActivityIndicator.js b/packages/react-native/Libraries/Components/ActivityIndicator/ActivityIndicator.js
index 3200bb8afc56..f021d43aad26 100644
--- a/packages/react-native/Libraries/Components/ActivityIndicator/ActivityIndicator.js
+++ b/packages/react-native/Libraries/Components/ActivityIndicator/ActivityIndicator.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -115,7 +115,7 @@ const ActivityIndicator: component(
   style,
   ...restProps
 }: {
-  ref?: any,
+  ref?: React.RefSetter<ActivityIndicatorInstance>,
   ...ActivityIndicatorProps,
 }) => {
   let sizeStyle;
diff --git a/packages/react-native/Libraries/Components/Button.js b/packages/react-native/Libraries/Components/Button.js
index c1bec4b65edf..7855575dbf80 100644
--- a/packages/react-native/Libraries/Components/Button.js
+++ b/packages/react-native/Libraries/Components/Button.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -232,7 +232,7 @@ const Button: component(
   } = props;
   const buttonStyles: Array<ViewStyleProp> = [styles.button];
   const textStyles: Array<TextStyleProp> = [styles.text];
-  if (color) {
+  if (color != null && color !== '' && color !== 0) {
     if (Platform.OS === 'ios') {
       textStyles.push({color: color});
     } else {
@@ -256,7 +256,7 @@ const Button: component(
       ? {..._accessibilityState, disabled}
       : _accessibilityState;
 
-  if (disabled) {
+  if (disabled === true) {
     buttonStyles.push(styles.buttonDisabled);
     textStyles.push(styles.textDisabled);
   }
@@ -279,7 +279,9 @@ const Button: component(
       accessible={accessible}
       accessibilityActions={accessibilityActions}
       onAccessibilityAction={onAccessibilityAction}
-      accessibilityLabel={ariaLabel || accessibilityLabel}
+      accessibilityLabel={
+        ariaLabel != null && ariaLabel !== '' ? ariaLabel : accessibilityLabel
+      }
       accessibilityHint={accessibilityHint}
       accessibilityLanguage={accessibilityLanguage}
       accessibilityRole="button"
diff --git a/packages/react-native/Libraries/Components/DrawerAndroid/DrawerLayoutAndroid.android.js b/packages/react-native/Libraries/Components/DrawerAndroid/DrawerLayoutAndroid.android.js
index 77c72316cfe8..0ee0b92b667c 100644
--- a/packages/react-native/Libraries/Components/DrawerAndroid/DrawerLayoutAndroid.android.js
+++ b/packages/react-native/Libraries/Components/DrawerAndroid/DrawerLayoutAndroid.android.js
@@ -4,10 +4,12 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
+// flowlint unsafe-getters-setters:off
+
 import type {
   MeasureInWindowOnSuccessCallback,
   MeasureLayoutOnSuccessCallback,
@@ -204,7 +206,7 @@ class DrawerLayoutAndroid
     );
   }
 
-  setNativeProps(nativeProps: Object) {
+  setNativeProps(nativeProps: {...}) {
     nullthrows(this._nativeRef.current).setNativeProps(nativeProps);
   }
 }
diff --git a/packages/react-native/Libraries/Components/DrawerAndroid/DrawerLayoutAndroid.js b/packages/react-native/Libraries/Components/DrawerAndroid/DrawerLayoutAndroid.js
index 5776fd4f500e..0bf8cca18b4d 100644
--- a/packages/react-native/Libraries/Components/DrawerAndroid/DrawerLayoutAndroid.js
+++ b/packages/react-native/Libraries/Components/DrawerAndroid/DrawerLayoutAndroid.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
diff --git a/packages/react-native/Libraries/Components/DrawerAndroid/DrawerLayoutAndroidTypes.js b/packages/react-native/Libraries/Components/DrawerAndroid/DrawerLayoutAndroidTypes.js
index c5b16a13e090..cbe137320123 100644
--- a/packages/react-native/Libraries/Components/DrawerAndroid/DrawerLayoutAndroidTypes.js
+++ b/packages/react-native/Libraries/Components/DrawerAndroid/DrawerLayoutAndroidTypes.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -127,7 +127,7 @@ export interface DrawerLayoutAndroidMethods {
     onSuccess: MeasureLayoutOnSuccessCallback,
     onFail?: () => void,
   ): void;
-  setNativeProps(nativeProps: Object): void;
+  setNativeProps(nativeProps: {...}): void;
 }
 
 export type DrawerLayoutAndroidInstance = DrawerLayoutAndroidMethods;
diff --git a/packages/react-native/Libraries/Components/StatusBar/StatusBar.js b/packages/react-native/Libraries/Components/StatusBar/StatusBar.js
index 0cd2315373ae..bab23467263c 100644
--- a/packages/react-native/Libraries/Components/StatusBar/StatusBar.js
+++ b/packages/react-native/Libraries/Components/StatusBar/StatusBar.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -101,13 +101,25 @@ export type StatusBarProps = Readonly<{
 
 type StackProps = {
   barStyle: ?{
-    value: StatusBarProps['barStyle'],
+    value: StatusBarStyle,
     animated: boolean,
   },
   hidden: ?{
     value: boolean,
     animated: boolean,
-    transition: StatusBarProps['showHideTransition'],
+    transition: StatusBarAnimation,
+  },
+};
+
+type ResolvedStackProps = {
+  barStyle: {
+    value: StatusBarStyle,
+    animated: boolean,
+  },
+  hidden: {
+    value: boolean,
+    animated: boolean,
+    transition: StatusBarAnimation,
   },
 };
 
@@ -126,13 +138,16 @@ function getAutoBarStyle(): 'light-content' | 'dark-content' {
  * barStyle to a concrete value.
  */
 function mergePropsStack(
-  propsStack: Array<Object>,
-  defaultValues: Object,
-): Object {
-  const merged: StackProps = propsStack.reduce(
+  propsStack: Array<StackProps>,
+  defaultValues: ResolvedStackProps,
+): ResolvedStackProps {
+  const merged: ResolvedStackProps = propsStack.reduce(
     (prev, cur) => {
       for (const prop in cur) {
+        // $FlowFixMe[invalid-computed-prop] dynamic merge over the known StackProps keys
         if (cur[prop] != null) {
+          // $FlowFixMe[invalid-computed-prop] dynamic merge over the known StackProps keys
+          // $FlowFixMe[prop-missing] dynamic merge over the known StackProps keys
           prev[prop] = cur[prop];
         }
       }
@@ -141,7 +156,7 @@ function mergePropsStack(
     {...defaultValues},
   );
 
-  if (merged.barStyle?.value === 'auto') {
+  if (merged.barStyle.value === 'auto') {
     merged.barStyle = {...merged.barStyle, value: getAutoBarStyle()};
   }
 
@@ -224,10 +239,10 @@ function createStackEntry(props: StatusBarProps): StackProps {
 class StatusBar extends React.Component<StatusBarProps> {
   static _propsStack: Array<StackProps> = [];
 
-  static _defaultProps: any = createStackEntry({
-    barStyle: 'default',
-    hidden: false,
-  });
+  static _defaultProps: ResolvedStackProps = {
+    barStyle: {value: 'default', animated: false},
+    hidden: {value: false, animated: false, transition: 'fade'},
+  };
 
   // Timer for updating the native module values at the end of the frame.
   static _updateImmediate: ?number = null;
@@ -235,7 +250,7 @@ class StatusBar extends React.Component<StatusBarProps> {
   // The current merged values from the props stack. `barStyle.value` is stored
   // in its resolved form (never `'auto'`), so diff comparisons reflect what
   // was actually sent to the native module.
-  static _currentValues: ?StackProps = null;
+  static _currentValues: ?ResolvedStackProps = null;
 
   // Number of mounted `StatusBar` instances. Used to lazily subscribe to color
   // scheme changes only while at least one instance is on screen.
@@ -264,10 +279,10 @@ class StatusBar extends React.Component<StatusBarProps> {
    *    changing the status bar hidden property.
    */
   static setHidden(hidden: boolean, animation?: StatusBarAnimation) {
-    animation = animation || 'none';
+    const resolvedAnimation = animation ?? 'none';
     StatusBar._defaultProps.hidden.value = hidden;
     if (Platform.OS === 'ios') {
-      NativeStatusBarManagerIOS.setHidden(hidden, animation);
+      NativeStatusBarManagerIOS.setHidden(hidden, resolvedAnimation);
     } else if (Platform.OS === 'android') {
       NativeStatusBarManagerAndroid.setHidden(hidden);
     }
@@ -279,11 +294,11 @@ class StatusBar extends React.Component<StatusBarProps> {
    * @param animated Animate the style change.
    */
   static setBarStyle(style: StatusBarStyle, animated?: boolean) {
-    animated = animated || false;
+    const resolvedAnimated = animated ?? false;
     StatusBar._defaultProps.barStyle.value = style;
     const resolvedStyle = style === 'auto' ? getAutoBarStyle() : style;
     if (Platform.OS === 'ios') {
-      NativeStatusBarManagerIOS.setStyle(resolvedStyle, animated);
+      NativeStatusBarManagerIOS.setStyle(resolvedStyle, resolvedAnimated);
     } else if (Platform.OS === 'android') {
       NativeStatusBarManagerAndroid.setStyle(resolvedStyle);
     }
diff --git a/packages/react-native/Libraries/Components/Touchable/PooledClass.js b/packages/react-native/Libraries/Components/Touchable/PooledClass.js
index 224c17bd295e..d831176f65af 100644
--- a/packages/react-native/Libraries/Components/Touchable/PooledClass.js
+++ b/packages/react-native/Libraries/Components/Touchable/PooledClass.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -20,6 +20,7 @@ import invariant from 'invariant';
  */
 /* $FlowFixMe[missing-this-annot] The 'this' type annotation(s) required by
  * Flow's LTI update could not be added via codemod */
+// $FlowFixMe[unclear-type]
 const oneArgumentPooler = function (copyFieldsFrom: any) {
   const Klass = this; // eslint-disable-line consistent-this
   if (Klass.instancePool.length) {
@@ -33,6 +34,7 @@ const oneArgumentPooler = function (copyFieldsFrom: any) {
 
 /* $FlowFixMe[missing-this-annot] The 'this' type annotation(s) required by
  * Flow's LTI update could not be added via codemod */
+// $FlowFixMe[unclear-type]
 const twoArgumentPooler = function (a1: any, a2: any) {
   const Klass = this; // eslint-disable-line consistent-this
   if (Klass.instancePool.length) {
@@ -46,6 +48,7 @@ const twoArgumentPooler = function (a1: any, a2: any) {
 
 /* $FlowFixMe[missing-this-annot] The 'this' type annotation(s) required by
  * Flow's LTI update could not be added via codemod */
+// $FlowFixMe[unclear-type]
 const threeArgumentPooler = function (a1: any, a2: any, a3: any) {
   const Klass = this; // eslint-disable-line consistent-this
   if (Klass.instancePool.length) {
@@ -59,6 +62,7 @@ const threeArgumentPooler = function (a1: any, a2: any, a3: any) {
 
 /* $FlowFixMe[missing-this-annot] The 'this' type annotation(s) required by
  * Flow's LTI update could not be added via codemod */
+// $FlowFixMe[unclear-type]
 const fourArgumentPooler = function (a1: any, a2: any, a3: any, a4: any) {
   const Klass = this; // eslint-disable-line consistent-this
   if (Klass.instancePool.length) {
@@ -89,6 +93,7 @@ const standardReleaser = function (instance) {
 const DEFAULT_POOL_SIZE = 10;
 const DEFAULT_POOLER = oneArgumentPooler;
 
+// $FlowFixMe[unclear-type]
 type Pooler = any;
 
 /**
@@ -112,6 +117,7 @@ const addPoolingTo = function <T>(
 } {
   // Casting as any so that flow ignores the actual implementation and trusts
   // it to match the type we declared
+  // $FlowFixMe[unclear-type]
   const NewKlass: any = CopyConstructor;
   NewKlass.instancePool = [];
   NewKlass.getPooled = pooler || DEFAULT_POOLER;
diff --git a/packages/react-native/Libraries/Components/Touchable/Touchable.js b/packages/react-native/Libraries/Components/Touchable/Touchable.js
index 827477f98c5b..8c5605366426 100644
--- a/packages/react-native/Libraries/Components/Touchable/Touchable.js
+++ b/packages/react-native/Libraries/Components/Touchable/Touchable.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -331,7 +331,7 @@ const TouchableMixinImpl = {
    */
   /* $FlowFixMe[missing-this-annot] The 'this' type annotation(s) required by
    * Flow's LTI update could not be added via codemod */
-  touchableHandleResponderTerminationRequest: function (): any {
+  touchableHandleResponderTerminationRequest: function (): boolean {
     return !this.props.rejectResponderTermination;
   },
 
@@ -340,7 +340,7 @@ const TouchableMixinImpl = {
    */
   /* $FlowFixMe[missing-this-annot] The 'this' type annotation(s) required by
    * Flow's LTI update could not be added via codemod */
-  touchableHandleStartShouldSetResponder: function (): any {
+  touchableHandleStartShouldSetResponder: function (): boolean {
     return !this.props.disabled;
   },
 
diff --git a/packages/react-native/Libraries/Core/Timers/JSTimers.js b/packages/react-native/Libraries/Core/Timers/JSTimers.js
index 82bd3c81de00..f196f54015c5 100644
--- a/packages/react-native/Libraries/Core/Timers/JSTimers.js
+++ b/packages/react-native/Libraries/Core/Timers/JSTimers.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  * @deprecated
  */
@@ -29,13 +29,15 @@ export type JSTimerType =
   | 'queueReactNativeMicrotask'
   | 'requestIdleCallback';
 
+type TimerFunc = (...args: Array<unknown>) => unknown;
+
 // These timing constants should be kept in sync with the ones in native ios and
 // android `RCTTiming` module.
 const FRAME_DURATION = 1000 / 60;
 const IDLE_CALLBACK_FRAME_DEADLINE = 1;
 
 // Parallel arrays
-const callbacks: Array<?Function> = [];
+const callbacks: Array<?TimerFunc> = [];
 const types: Array<?JSTimerType> = [];
 const timerIDs: Array<?number> = [];
 const freeIdxs: Array<number> = [];
@@ -57,7 +59,7 @@ function _getFreeIndex(): number {
   return freeIdx;
 }
 
-function _allocateCallback(func: Function, type: JSTimerType): number {
+function _allocateCallback(func: TimerFunc, type: JSTimerType): number {
   const id = GUID++;
   const freeIndex = _getFreeIndex();
   timerIDs[freeIndex] = id;
@@ -210,9 +212,9 @@ const JSTimers = {
    * @param {number} duration Number of milliseconds.
    */
   setTimeout: function (
-    func: Function,
+    func: TimerFunc,
     duration: number,
-    ...args: any
+    ...args: Array<unknown>
   ): number {
     const id = _allocateCallback(
       () => func.apply(undefined, args),
@@ -227,9 +229,9 @@ const JSTimers = {
    * @param {number} duration Number of milliseconds.
    */
   setInterval: function (
-    func: Function,
+    func: TimerFunc,
     duration: number,
-    ...args: any
+    ...args: Array<unknown>
   ): number {
     const id = _allocateCallback(
       () => func.apply(undefined, args),
@@ -247,7 +249,10 @@ const JSTimers = {
    * @param {function} func Callback to be invoked before the end of the
    * current JavaScript execution loop.
    */
-  queueReactNativeMicrotask: function (func: Function, ...args: any): number {
+  queueReactNativeMicrotask: function (
+    func: TimerFunc,
+    ...args: Array<unknown>
+  ): number {
     const id = _allocateCallback(
       () => func.apply(undefined, args),
       'queueReactNativeMicrotask',
@@ -259,7 +264,7 @@ const JSTimers = {
   /**
    * @param {function} func Callback to be invoked every frame.
    */
-  requestAnimationFrame: function (func: Function): any | number {
+  requestAnimationFrame: function (func: TimerFunc): number {
     const id = _allocateCallback(func, 'requestAnimationFrame');
     createTimer(id, 1, Date.now(), /* recurring */ false);
     return id;
@@ -271,9 +276,9 @@ const JSTimers = {
    * @param {?object} options
    */
   requestIdleCallback: function (
-    func: Function,
-    options: ?Object,
-  ): any | number {
+    func: TimerFunc,
+    options: ?{timeout?: number, ...},
+  ): number {
     if (requestIdleCallbacks.length === 0) {
       setSendIdleEvents(true);
     }
@@ -281,7 +286,7 @@ const JSTimers = {
     const timeout = options && options.timeout;
     const id: number = _allocateCallback(
       timeout != null
-        ? (deadline: any) => {
+        ? (deadline: unknown) => {
             const timeoutId: number = requestIdleCallbackTimeouts[id];
             if (timeoutId) {
               JSTimers.clearTimeout(timeoutId);
@@ -353,7 +358,7 @@ const JSTimers = {
    * This is called from the native side. We are passed an array of timerIDs,
    * and
    */
-  callTimers: function (timersToCall: Array<number>): any | void {
+  callTimers: function (timersToCall: Array<number>): void {
     invariant(
       timersToCall.length !== 0,
       'Cannot call `callTimers` with an empty list of IDs.',
@@ -458,20 +463,34 @@ function setSendIdleEvents(sendIdleEvents: boolean): void {
 }
 
 let ExportedJSTimers: {
-  callIdleCallbacks: (frameTime: number) => any | void,
+  callIdleCallbacks: (frameTime: number) => void,
   callReactNativeMicrotasks: () => void,
-  callTimers: (timersToCall: Array<number>) => any | void,
+  callTimers: (timersToCall: Array<number>) => void,
   cancelAnimationFrame: (timerID: number) => void,
   cancelIdleCallback: (timerID: number) => void,
   clearReactNativeMicrotask: (timerID: number) => void,
   clearInterval: (timerID: number) => void,
   clearTimeout: (timerID: number) => void,
-  emitTimeDriftWarning: (warningMessage: string) => any | void,
-  requestAnimationFrame: (func: any) => any | number,
-  requestIdleCallback: (func: any, options: ?any) => any | number,
-  queueReactNativeMicrotask: (func: any, ...args: any) => number,
-  setInterval: (func: any, duration: number, ...args: any) => number,
-  setTimeout: (func: any, duration: number, ...args: any) => number,
+  emitTimeDriftWarning: (warningMessage: string) => void,
+  requestAnimationFrame: (func: TimerFunc) => number,
+  requestIdleCallback: (
+    func: TimerFunc,
+    options: ?{timeout?: number, ...},
+  ) => number,
+  queueReactNativeMicrotask: (
+    func: TimerFunc,
+    ...args: Array<unknown>
+  ) => number,
+  setInterval: (
+    func: TimerFunc,
+    duration: number,
+    ...args: Array<unknown>
+  ) => number,
+  setTimeout: (
+    func: TimerFunc,
+    duration: number,
+    ...args: Array<unknown>
+  ) => number,
 };
 
 if (!NativeTiming) {
diff --git a/packages/react-native/Libraries/Core/Timers/immediateShim.js b/packages/react-native/Libraries/Core/Timers/immediateShim.js
index 6e9534de1621..df84d573ed3f 100644
--- a/packages/react-native/Libraries/Core/Timers/immediateShim.js
+++ b/packages/react-native/Libraries/Core/Timers/immediateShim.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  * @deprecated
  */
@@ -22,7 +22,10 @@ const clearedImmediates: Set<number> = new Set();
  * @param {function} func Callback to be invoked before the end of the
  * current JavaScript execution loop.
  */
-export function setImmediate(callback: Function, ...args: any): number {
+export function setImmediate<TArgs extends Array<unknown>>(
+  callback: (...args: TArgs) => unknown,
+  ...args: TArgs
+): number {
   if (arguments.length < 1) {
     throw new TypeError(
       'setImmediate must be called with at least one argument (a function to call)',
@@ -41,7 +44,6 @@ export function setImmediate(callback: Function, ...args: any): number {
     clearedImmediates.delete(id);
   }
 
-  // $FlowFixMe[incompatible-type]
   global.queueMicrotask(() => {
     if (!clearedImmediates.has(id)) {
       callback.apply(undefined, args);
diff --git a/packages/react-native/Libraries/Core/Timers/queueMicrotask.js b/packages/react-native/Libraries/Core/Timers/queueMicrotask.js
index 34741aa1f838..efc8a3da277f 100644
--- a/packages/react-native/Libraries/Core/Timers/queueMicrotask.js
+++ b/packages/react-native/Libraries/Core/Timers/queueMicrotask.js
@@ -4,13 +4,13 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
 'use strict';
 
-let resolvedPromise;
+let resolvedPromise: ?Promise<void>;
 
 /**
  * Polyfill for the microtask queueing API defined by WHATWG HTML spec.
@@ -19,7 +19,7 @@ let resolvedPromise;
  * The method must queue a microtask to invoke @param {function} callback, and
  * if the callback throws an exception, report the exception.
  */
-export default function queueMicrotask(callback: Function) {
+export default function queueMicrotask(callback: () => unknown) {
   if (arguments.length < 1) {
     throw new TypeError(
       'queueMicrotask must be called with at least one argument (a function to call)',
@@ -30,7 +30,6 @@ export default function queueMicrotask(callback: Function) {
   }
 
   // Try to reuse a lazily allocated resolved promise from closure.
-  // $FlowFixMe[constant-condition]
   (resolvedPromise || (resolvedPromise = Promise.resolve()))
     .then(callback)
     .catch(error =>
diff --git a/packages/react-native/Libraries/Core/setUpReactDevTools.js b/packages/react-native/Libraries/Core/setUpReactDevTools.js
index 0e5a7aeb6779..f5bc1ccf7bf7 100644
--- a/packages/react-native/Libraries/Core/setUpReactDevTools.js
+++ b/packages/react-native/Libraries/Core/setUpReactDevTools.js
@@ -4,13 +4,16 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
 'use strict';
 
-import type {Domain} from '../../src/private/devsupport/rndevtools/setUpFuseboxReactDevToolsDispatcher';
+import type {
+  Domain,
+  JSONValue,
+} from '../../src/private/devsupport/rndevtools/setUpFuseboxReactDevToolsDispatcher';
 import type {Spec as NativeReactDevToolsRuntimeSettingsModuleSpec} from '../../src/private/devsupport/rndevtools/specs/NativeReactDevToolsRuntimeSettingsModule';
 
 if (__DEV__) {
@@ -35,6 +38,7 @@ if (__DEV__) {
   const {
     initialize,
     connectWithCustomMessagingProtocol,
+    // $FlowFixMe[untyped-import]
   } = require('react-devtools-core');
 
   const reactDevToolsSettingsManager = require('../../src/private/devsupport/rndevtools/ReactDevToolsSettingsManager');
@@ -73,7 +77,7 @@ if (__DEV__) {
     require('../Components/View/ReactNativeStyleAttributes').default;
   const resolveRNStyle = require('../StyleSheet/flattenStyle').default;
 
-  function handleReactDevToolsSettingsUpdate(settings: Object) {
+  function handleReactDevToolsSettingsUpdate(settings: {[string]: unknown}) {
     reactDevToolsSettingsManager.setGlobalHookSettings(
       JSON.stringify(settings),
     );
@@ -97,13 +101,13 @@ if (__DEV__) {
       maybeReactDevToolsRuntimeSettingsModuleModule,
     );
     disconnect = connectWithCustomMessagingProtocol({
-      onSubscribe: listener => {
+      onSubscribe: (listener: (message: JSONValue) => void) => {
         domain.onMessage.addEventListener(listener);
       },
-      onUnsubscribe: listener => {
+      onUnsubscribe: (listener: (message: JSONValue) => void) => {
         domain.onMessage.removeEventListener(listener);
       },
-      onMessage: (event, payload) => {
+      onMessage: (event: string, payload: JSONValue) => {
         domain.sendMessage({event, payload});
       },
       nativeStyleEditorValidAttributes: Object.keys(ReactNativeStyleAttributes),
diff --git a/packages/react-native/Libraries/Core/setUpReactRefresh.js b/packages/react-native/Libraries/Core/setUpReactRefresh.js
index be8844dcf344..7c4a272fd73b 100644
--- a/packages/react-native/Libraries/Core/setUpReactRefresh.js
+++ b/packages/react-native/Libraries/Core/setUpReactRefresh.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -18,6 +18,7 @@ if (__DEV__) {
   }
 
   // This needs to run before the renderer initializes.
+  // $FlowFixMe[untyped-import]
   const ReactRefreshRuntime = require('react-refresh/runtime');
   ReactRefreshRuntime.injectIntoGlobalHook(global);
 
diff --git a/packages/react-native/Libraries/EventEmitter/RCTEventEmitter.js b/packages/react-native/Libraries/EventEmitter/RCTEventEmitter.js
index 069caedcb254..3e5bb8e66242 100644
--- a/packages/react-native/Libraries/EventEmitter/RCTEventEmitter.js
+++ b/packages/react-native/Libraries/EventEmitter/RCTEventEmitter.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -12,8 +12,22 @@
 
 import registerCallableModule from '../Core/registerCallableModule';
 
+type EventEmitterModule = {
+  receiveEvent: (
+    rootNodeID: number,
+    topLevelType: string,
+    nativeEventParam: unknown,
+  ) => void,
+  receiveTouches: (
+    eventTopLevelType: string,
+    touches: Array<unknown>,
+    changedIndices: Array<number>,
+  ) => void,
+  ...
+};
+
 const RCTEventEmitter = {
-  register(eventEmitter: any) {
+  register(eventEmitter: EventEmitterModule) {
     registerCallableModule('RCTEventEmitter', eventEmitter);
   },
 };
diff --git a/packages/react-native/Libraries/Interaction/PanResponder.js b/packages/react-native/Libraries/Interaction/PanResponder.js
index 3c31c1a895c9..fbf0a5d5f0b2 100644
--- a/packages/react-native/Libraries/Interaction/PanResponder.js
+++ b/packages/react-native/Libraries/Interaction/PanResponder.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
diff --git a/packages/react-native/Libraries/Lists/FlatList.js b/packages/react-native/Libraries/Lists/FlatList.js
index ff4563be2406..6976a324b8dc 100644
--- a/packages/react-native/Libraries/Lists/FlatList.js
+++ b/packages/react-native/Libraries/Lists/FlatList.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -78,10 +78,10 @@ type OptionalFlatListProps<ItemT> = {
    * any of your `renderItem`, Header, Footer, etc. functions depend on anything outside of the
    * `data` prop, stick it here and treat it immutably.
    */
-  extraData?: any,
+  extraData?: unknown,
   /**
    * `getItemLayout` is an optional optimizations that let us skip measurement of dynamic content if
-   * you know the height of items a priori. `getItemLayout` is the most efficient, and is easy to
+   * you know the height of items a priori.
    * use if you have fixed height items, for example:
    *
    *     getItemLayout={(data, index) => (
@@ -305,6 +305,7 @@ export type FlatListProps<ItemT> = Readonly<{
  *
  * Also inherits [ScrollView Props](docs/scrollview.html#props), unless it is nested in another FlatList of same orientation.
  */
+// flowlint-next-line unclear-type:off
 class FlatList<ItemT = any> extends React.PureComponent<FlatListProps<ItemT>> {
   /**
    * Scrolls to the end of the content. May be janky without `getItemLayout` prop.
@@ -404,6 +405,7 @@ class FlatList<ItemT = any> extends React.PureComponent<FlatListProps<ItemT>> {
     }
   }
 
+  // flowlint-next-line unclear-type:off
   getScrollableNode(): any {
     if (this._listRef) {
       return this._listRef.getScrollableNode();
@@ -499,7 +501,7 @@ class FlatList<ItemT = any> extends React.PureComponent<FlatListProps<ItemT>> {
       'FlatList does not support custom data formats.',
     );
     if (numColumns > 1) {
-      invariant(!horizontal, 'numColumns does not support horizontal.');
+      invariant(horizontal !== true, 'numColumns does not support horizontal.');
     } else {
       invariant(
         !columnWrapperStyle,
@@ -611,11 +613,13 @@ class FlatList<ItemT = any> extends React.PureComponent<FlatListProps<ItemT>> {
   }
 
   _renderer = (
-    ListItemComponent: ?(React.ComponentType<any> | React.MixedElement),
+    ListItemComponent: ?(
+      React.ComponentType<ListRenderItemInfo<ItemT>> | React.MixedElement
+    ),
     renderItem: ?ListRenderItem<ItemT>,
     columnWrapperStyle: ?ViewStyleProp,
     numColumns: ?number,
-    extraData: ?any,
+    extraData: ?unknown,
     // $FlowFixMe[missing-local-annot]
   ) => {
     const cols = numColumnsOrDefault(numColumns);
diff --git a/packages/react-native/Libraries/Lists/SectionList.js b/packages/react-native/Libraries/Lists/SectionList.js
index 9aa96b248aaa..bfc00d9be648 100644
--- a/packages/react-native/Libraries/Lists/SectionList.js
+++ b/packages/react-native/Libraries/Lists/SectionList.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -26,6 +26,7 @@ import * as React from 'react';
 const VirtualizedSectionList = VirtualizedLists.VirtualizedSectionList;
 
 type DefaultSectionT = {
+  // flowlint-next-line unclear-type:off
   [key: string]: any,
 };
 
@@ -74,7 +75,7 @@ type OptionalSectionListProps<ItemT, SectionT = DefaultSectionT> = {
    * any of your `renderItem`, Header, Footer, etc. functions depend on anything outside of the
    * `data` prop, stick it here and treat it immutably.
    */
-  extraData?: any,
+  extraData?: unknown,
   /**
    * How many items to render in the initial batch. This should be enough to fill the screen but not
    * much more. Note these items will never be unmounted as part of the windowed rendering in order
@@ -172,6 +173,7 @@ export type SectionListProps<ItemT, SectionT = DefaultSectionT> = {
  * @see https://reactnative.dev/docs/sectionlist
  */
 export default class SectionList<
+  // flowlint-next-line unclear-type:off
   ItemT = any,
   SectionT = DefaultSectionT,
 > extends React.PureComponent<SectionListProps<ItemT, SectionT>> {
@@ -226,6 +228,7 @@ export default class SectionList<
   /**
    * Provides a handle to the underlying scroll node.
    */
+  // flowlint-next-line unclear-type:off
   getScrollableNode(): any {
     const listRef = this._wrapperListRef && this._wrapperListRef.getListRef();
     if (listRef) {
@@ -233,6 +236,7 @@ export default class SectionList<
     }
   }
 
+  // flowlint-next-line unclear-type:off
   setNativeProps(props: Object) {
     const listRef = this._wrapperListRef && this._wrapperListRef.getListRef();
     if (listRef) {
diff --git a/packages/react-native/Libraries/Lists/SectionListModern.js b/packages/react-native/Libraries/Lists/SectionListModern.js
index 2661a31bc326..9ec7d56002c2 100644
--- a/packages/react-native/Libraries/Lists/SectionListModern.js
+++ b/packages/react-native/Libraries/Lists/SectionListModern.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -26,6 +26,7 @@ import {useImperativeHandle, useRef} from 'react';
 const VirtualizedSectionList = VirtualizedLists.VirtualizedSectionList;
 
 type DefaultSectionT = {
+  // flowlint-next-line unclear-type:off
   [key: string]: any,
 };
 
@@ -60,6 +61,7 @@ type OptionalProps<ItemT, SectionT = DefaultSectionT> = {
     separators: {
       highlight: () => void,
       unhighlight: () => void,
+      // flowlint-next-line unclear-type:off
       updateProps: (select: 'leading' | 'trailing', newProps: Object) => void,
       ...
     },
@@ -70,6 +72,7 @@ type OptionalProps<ItemT, SectionT = DefaultSectionT> = {
    * any of your `renderItem`, Header, Footer, etc. functions depend on anything outside of the
    * `data` prop, stick it here and treat it immutably.
    */
+  // flowlint-next-line unclear-type:off
   extraData?: any,
   /**
    * How many items to render in the initial batch. This should be enough to fill the screen but not
@@ -110,6 +113,9 @@ export type Props<ItemT, SectionT = DefaultSectionT> = Readonly<{
   ...OptionalProps<ItemT, SectionT>,
 }>;
 
+// flowlint-next-line unclear-type:off
+type SectionListComponentProps = Props<any, DefaultSectionT>;
+
 /**
  * A performant interface for rendering sectioned lists, supporting the most handy features:
  *
@@ -166,14 +172,16 @@ export type Props<ItemT, SectionT = DefaultSectionT> = Readonly<{
  *
  */
 const SectionList: component(
+  // flowlint-next-line unclear-type:off
   ref?: React.RefSetter<any>,
-  ...Props<any, DefaultSectionT>
+  ...SectionListComponentProps
 ) = ({
   ref,
   ...props
 }: {
+  // flowlint-next-line unclear-type:off
   ref?: React.RefSetter<any>,
-  ...Props<any, DefaultSectionT>,
+  ...SectionListComponentProps,
 }) => {
   const propsWithDefaults = {
     stickySectionHeadersEnabled: Platform.OS === 'ios',
@@ -224,11 +232,12 @@ const SectionList: component(
         wrapperRef.current?.getListRef()?.getScrollResponder();
       },
 
+      // flowlint-next-line unclear-type:off
       getScrollableNode(): any {
         wrapperRef.current?.getListRef()?.getScrollableNode();
       },
 
-      setNativeProps(nativeProps: Object) {
+      setNativeProps(nativeProps: {[string]: unknown}) {
         wrapperRef.current?.getListRef()?.setNativeProps(nativeProps);
       },
     }),
diff --git a/packages/react-native/Libraries/Lists/__flowtests__/SectionList-flowtest.js b/packages/react-native/Libraries/Lists/__flowtests__/SectionList-flowtest.js
index 9f5a7efd2000..769e0da32376 100644
--- a/packages/react-native/Libraries/Lists/__flowtests__/SectionList-flowtest.js
+++ b/packages/react-native/Libraries/Lists/__flowtests__/SectionList-flowtest.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -22,7 +22,7 @@ function renderMyListItem(info: {
 const renderMyHeader = ({
   section,
 }: {
-  section: {fooNumber: number, ...} & Object,
+  section: {fooNumber: number, ...},
   ...
 }) => <span />;
 
diff --git a/packages/react-native/Libraries/LogBox/UI/AnsiHighlight.js b/packages/react-native/Libraries/LogBox/UI/AnsiHighlight.js
index 8871f67c6bb0..26f25b6b8578 100644
--- a/packages/react-native/Libraries/LogBox/UI/AnsiHighlight.js
+++ b/packages/react-native/Libraries/LogBox/UI/AnsiHighlight.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -13,6 +13,7 @@ import type {TextStyleProp} from '../../StyleSheet/StyleSheet';
 import View from '../../Components/View/View';
 import StyleSheet from '../../StyleSheet/StyleSheet';
 import Text from '../../Text/Text';
+// $FlowFixMe[untyped-import]
 import {ansiToJson} from 'anser';
 import * as React from 'react';
 
diff --git a/packages/react-native/Libraries/Network/FormData.js b/packages/react-native/Libraries/Network/FormData.js
index 3e7b02e669dc..551a1eca57f9 100644
--- a/packages/react-native/Libraries/Network/FormData.js
+++ b/packages/react-native/Libraries/Network/FormData.js
@@ -14,7 +14,7 @@ type FormDataValue = string | {name?: string, type?: string, uri: string};
 type FormDataNameValuePair = [string, FormDataValue];
 
 type Headers = {[name: string]: string, ...};
-type FormDataPart =
+export type FormDataPart =
   | {
       string: string,
       headers: Headers,
diff --git a/packages/react-native/Libraries/Network/RCTNetworking.android.js b/packages/react-native/Libraries/Network/RCTNetworking.android.js
index c79b584a4d3c..846467f19ab4 100644
--- a/packages/react-native/Libraries/Network/RCTNetworking.android.js
+++ b/packages/react-native/Libraries/Network/RCTNetworking.android.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -21,10 +21,11 @@ import convertRequestBody from './convertRequestBody';
 import NativeNetworkingAndroid from './NativeNetworkingAndroid';
 
 type Header = [string, string];
+type HeadersMap = {[string]: string};
 
 // Convert FormData headers to arrays, which are easier to consume in
 // native on Android.
-function convertHeadersMapToArray(headers: Object): Array<Header> {
+function convertHeadersMapToArray(headers: HeadersMap): Array<Header> {
   const headerArray: Array<Header> = [];
   for (const name in headers) {
     headerArray.push([name, headers[name]]);
@@ -37,7 +38,7 @@ function generateRequestId(): number {
   return _requestId++;
 }
 
-const emitter = new NativeEventEmitter<$FlowFixMe>(
+const emitter = new NativeEventEmitter<RCTNetworkingEventDefinitions>(
   // T88715063: NativeEventEmitter only used this parameter on iOS. Now it uses it on all platforms, so this code was modified automatically to preserve its behavior
   // If you want to use the native module on other platforms, please remove this condition and test its behavior
   Platform.OS !== 'ios' ? null : NativeNetworkingAndroid,
@@ -53,7 +54,6 @@ const RCTNetworking = {
     listener: (...RCTNetworkingEventDefinitions[K]) => unknown,
     context?: unknown,
   ): EventSubscription {
-    // $FlowFixMe[incompatible-type]
     return emitter.addListener(eventType, listener, context);
   },
 
@@ -61,8 +61,8 @@ const RCTNetworking = {
     method: string,
     trackingName: string | void,
     url: string,
-    headers: Object,
-    data: RequestBody,
+    headers: HeadersMap,
+    data: ?RequestBody,
     responseType: NativeResponseType,
     incrementalUpdates: boolean,
     timeout: number,
@@ -70,12 +70,17 @@ const RCTNetworking = {
     withCredentials: boolean,
   ) {
     const body = convertRequestBody(data);
-    if (body && body.formData) {
-      body.formData = body.formData.map(part => ({
-        ...part,
-        headers: convertHeadersMapToArray(part.headers),
-      }));
-    }
+    const formData = body.formData;
+    const nativeRequestBody =
+      formData != null
+        ? {
+            ...body,
+            formData: formData.map(part => ({
+              ...part,
+              headers: convertHeadersMapToArray(part.headers),
+            })),
+          }
+        : body;
     const requestId = generateRequestId();
     const devToolsRequestId =
       global.__NETWORK_REPORTER__?.createDevToolsRequestId();
@@ -84,7 +89,7 @@ const RCTNetworking = {
       url,
       requestId,
       convertHeadersMapToArray(headers),
-      {...body, trackingName, devToolsRequestId},
+      {...nativeRequestBody, trackingName, devToolsRequestId},
       responseType,
       incrementalUpdates,
       timeout,
diff --git a/packages/react-native/Libraries/Network/RCTNetworking.ios.js b/packages/react-native/Libraries/Network/RCTNetworking.ios.js
index a97c96dec1f9..79bb13c8e2c2 100644
--- a/packages/react-native/Libraries/Network/RCTNetworking.ios.js
+++ b/packages/react-native/Libraries/Network/RCTNetworking.ios.js
@@ -32,7 +32,7 @@ const RCTNetworking = {
     trackingName: string | void,
     url: string,
     headers: {...},
-    data: RequestBody,
+    data: ?RequestBody,
     responseType: NativeResponseType,
     incrementalUpdates: boolean,
     timeout: number,
diff --git a/packages/react-native/Libraries/Network/RCTNetworking.js.flow b/packages/react-native/Libraries/Network/RCTNetworking.js.flow
index c1802972b4ea..d3dccfbe5006 100644
--- a/packages/react-native/Libraries/Network/RCTNetworking.js.flow
+++ b/packages/react-native/Libraries/Network/RCTNetworking.js.flow
@@ -27,8 +27,8 @@ declare const RCTNetworking: interface {
     method: string,
     trackingName: string | void,
     url: string,
-    headers: {...},
-    data: RequestBody,
+    headers: {[string]: string},
+    data: ?RequestBody,
     responseType: NativeResponseType,
     incrementalUpdates: boolean,
     timeout: number,
diff --git a/packages/react-native/Libraries/Network/XMLHttpRequest.js b/packages/react-native/Libraries/Network/XMLHttpRequest.js
index 7edb4c2a24c5..e60bf98d96d1 100644
--- a/packages/react-native/Libraries/Network/XMLHttpRequest.js
+++ b/packages/react-native/Libraries/Network/XMLHttpRequest.js
@@ -4,16 +4,19 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
+// flowlint unsafe-getters-setters:off
+
 'use strict';
 
 import type {
   EventCallback,
   EventListener,
 } from '../../src/private/webapis/dom/events/EventTarget';
+import type {RequestBody} from './convertRequestBody';
 
 import Event from '../../src/private/webapis/dom/events/Event';
 import {
@@ -30,20 +33,25 @@ const RCTNetworking = require('./RCTNetworking').default;
 const base64 = require('base64-js');
 const invariant = require('invariant');
 
-const DEBUG_NETWORK_SEND_DELAY: false = false; // Set to a number of milliseconds when debugging
+const DEBUG_NETWORK_SEND_DELAY: number = 0; // Set to a number of milliseconds when debugging
 
 export type NativeResponseType = 'base64' | 'blob' | 'text';
 export type ResponseType =
   '' | 'arraybuffer' | 'blob' | 'document' | 'json' | 'text';
-export type Response = ?Object | string;
+export type Response = unknown;
 
 type XHRInterceptor = interface {
-  requestSent(id: number, url: string, method: string, headers: Object): void,
+  requestSent(
+    id: number,
+    url: string,
+    method: string,
+    headers: {[string]: string},
+  ): void,
   responseReceived(
     id: number,
     url: string,
     status: number,
-    headers: Object,
+    headers: {[string]: string},
   ): void,
   dataReceived(id: number, data: string): void,
   loadingFinished(id: number, encodedDataLength: number): void,
@@ -145,7 +153,7 @@ class XMLHttpRequest extends EventTarget {
   DONE: number = DONE;
 
   readyState: number = UNSENT;
-  responseHeaders: ?Object;
+  responseHeaders: ?{[string]: string};
   status: number = 0;
   timeout: number = 0;
   responseURL: ?string;
@@ -159,8 +167,8 @@ class XMLHttpRequest extends EventTarget {
   _aborted: boolean = false;
   _cachedResponse: Response;
   _hasError: boolean = false;
-  _headers: Object;
-  _lowerCaseResponseHeaders: Object;
+  _headers: {[string]: string};
+  _lowerCaseResponseHeaders: {[string]: string};
   _method: ?string = null;
   _perfKey: ?string = null;
   _responseType: ResponseType;
@@ -305,8 +313,8 @@ class XMLHttpRequest extends EventTarget {
     XMLHttpRequest._interceptor &&
       XMLHttpRequest._interceptor.requestSent(
         requestId,
-        this._url || '',
-        this._method || 'GET',
+        this._url ?? '',
+        this._method != null && this._method !== '' ? this._method : 'GET',
         this._headers,
       );
   }
@@ -332,7 +340,7 @@ class XMLHttpRequest extends EventTarget {
   __didReceiveResponse(
     requestId: number,
     status: number,
-    responseHeaders: ?Object,
+    responseHeaders: ?{[string]: string},
     responseURL: ?string,
   ): void {
     if (requestId === this._requestId) {
@@ -343,7 +351,7 @@ class XMLHttpRequest extends EventTarget {
       this.status = status;
       this.setResponseHeaders(responseHeaders);
       this.setReadyState(this.HEADERS_RECEIVED);
-      if (responseURL || responseURL === '') {
+      if (responseURL != null) {
         this.responseURL = responseURL;
       } else {
         delete this.responseURL;
@@ -352,7 +360,9 @@ class XMLHttpRequest extends EventTarget {
       XMLHttpRequest._interceptor &&
         XMLHttpRequest._interceptor.responseReceived(
           requestId,
-          responseURL || this._url || '',
+          responseURL != null && responseURL !== ''
+            ? responseURL
+            : (this._url ?? ''),
           status,
           responseHeaders || {},
         );
@@ -509,7 +519,7 @@ class XMLHttpRequest extends EventTarget {
     return value !== undefined ? value : null;
   }
 
-  setRequestHeader(header: string, value: any): void {
+  setRequestHeader(header: string, value: string): void {
     if (this.readyState !== this.OPENED) {
       throw new Error('Request has not been opened');
     }
@@ -543,7 +553,7 @@ class XMLHttpRequest extends EventTarget {
     if (this.readyState !== this.UNSENT) {
       throw new Error('Cannot open, already sending');
     }
-    if (async !== undefined && !async) {
+    if (async !== undefined && async !== true) {
       // async is default
       throw new Error('Synchronous http requests are not supported');
     }
@@ -556,7 +566,7 @@ class XMLHttpRequest extends EventTarget {
     this.setReadyState(this.OPENED);
   }
 
-  send(data: any): void {
+  send(data: ?RequestBody): void {
     if (this.readyState !== this.OPENED) {
       throw new Error('Request has not been opened');
     }
@@ -614,12 +624,12 @@ class XMLHttpRequest extends EventTarget {
         performanceLogger.startTimespan(this._perfKey);
       }
       invariant(
-        this._method,
+        this._method != null && this._method !== '',
         'XMLHttpRequest method needs to be defined (%s).',
         friendlyName,
       );
       invariant(
-        this._url,
+        this._url != null && this._url !== '',
         'XMLHttpRequest URL needs to be defined (%s).',
         friendlyName,
       );
@@ -632,13 +642,10 @@ class XMLHttpRequest extends EventTarget {
         nativeResponseType,
         incrementalEvents,
         this.timeout,
-        // $FlowFixMe[method-unbinding] added when improving typing for this parameters
-        this.__didCreateRequest.bind(this),
+        (requestId: number) => this.__didCreateRequest(requestId),
         this.withCredentials,
       );
     };
-    /* $FlowFixMe[constant-condition] Error discovered during Constant
-     * Condition roll out. See https://fburl.com/workplace/1v97vimq. */
     if (DEBUG_NETWORK_SEND_DELAY) {
       setTimeout(doSend, DEBUG_NETWORK_SEND_DELAY);
     } else {
@@ -648,7 +655,7 @@ class XMLHttpRequest extends EventTarget {
 
   abort(): void {
     this._aborted = true;
-    if (this._requestId) {
+    if (this._requestId != null) {
       RCTNetworking.abortRequest(this._requestId);
     }
     // only call onreadystatechange if there is something to abort,
@@ -665,13 +672,12 @@ class XMLHttpRequest extends EventTarget {
     this._reset();
   }
 
-  setResponseHeaders(responseHeaders: ?Object): void {
+  setResponseHeaders(responseHeaders: ?{[string]: string}): void {
     this.responseHeaders = responseHeaders || null;
-    const headers = responseHeaders || {};
+    const headers: {[string]: string} = responseHeaders || {};
     this._lowerCaseResponseHeaders = Object.keys(headers).reduce<{
-      [string]: any,
+      [string]: string,
     }>((lcaseHeaders, headerName) => {
-      // $FlowFixMe[invalid-computed-prop]
       lcaseHeaders[headerName.toLowerCase()] = headers[headerName];
       return lcaseHeaders;
     }, {});
diff --git a/packages/react-native/Libraries/Network/convertRequestBody.js b/packages/react-native/Libraries/Network/convertRequestBody.js
index caf79174078d..91ac9d944eea 100644
--- a/packages/react-native/Libraries/Network/convertRequestBody.js
+++ b/packages/react-native/Libraries/Network/convertRequestBody.js
@@ -4,13 +4,15 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
 'use strict';
 
 import typeof BlobT from '../Blob/Blob';
+import type {BlobData} from '../Blob/BlobTypes';
+import type {FormDataPart} from './FormData';
 import typeof FormDataT from './FormData';
 
 const Blob: BlobT = require('../Blob/Blob').default;
@@ -25,7 +27,16 @@ export type RequestBody =
   | ArrayBuffer
   | $ArrayBufferView;
 
-function convertRequestBody(body: RequestBody): Object {
+type RequestBodyResult = Readonly<{
+  string?: string,
+  blob?: BlobData,
+  formData?: Array<FormDataPart>,
+  base64?: string,
+  uri?: string,
+  ...
+}>;
+
+function convertRequestBody(body: ?RequestBody): RequestBodyResult {
   if (typeof body === 'string') {
     return {string: body};
   }
@@ -35,12 +46,15 @@ function convertRequestBody(body: RequestBody): Object {
   if (body instanceof FormData) {
     return {formData: body.getParts()};
   }
+  if (body == null) {
+    return {};
+  }
   if (body instanceof ArrayBuffer || ArrayBuffer.isView(body)) {
     /* $FlowFixMe[incompatible-type] : no way to assert that 'body' is indeed
      * an ArrayBufferView */
     return {base64: binaryToBase64(body)};
   }
-  return body;
+  return {...body};
 }
 
 export default convertRequestBody;
diff --git a/packages/react-native/Libraries/PushNotificationIOS/PushNotificationIOS.js b/packages/react-native/Libraries/PushNotificationIOS/PushNotificationIOS.js
index a8a6774614bd..7de529ce4f8b 100644
--- a/packages/react-native/Libraries/PushNotificationIOS/PushNotificationIOS.js
+++ b/packages/react-native/Libraries/PushNotificationIOS/PushNotificationIOS.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -28,6 +28,7 @@ type PresentLocalNotificationDetails = {
   alertTitle?: string,
   soundName?: string,
   category?: string,
+  // $FlowFixMe[unclear-type]
   userInfo?: Object,
   applicationIconBadgeNumber?: number,
   fireDate?: number,
@@ -122,6 +123,7 @@ export interface PushNotification {
   /**
    * An alias for `getAlert` to get the notification's main message string
    */
+  // $FlowFixMe[unclear-type]
   getMessage(): ?string | ?Object;
 
   /**
@@ -137,6 +139,7 @@ export interface PushNotification {
   /**
    * Gets the notification's main message from the `aps` object
    */
+  // $FlowFixMe[unclear-type]
   getAlert(): ?string | ?Object;
 
   /**
@@ -152,6 +155,7 @@ export interface PushNotification {
   /**
    * Gets the data object on the notif
    */
+  // $FlowFixMe[unclear-type]
   getData(): ?Object;
 
   /**
@@ -174,7 +178,9 @@ export interface PushNotification {
  * @deprecated Use [@react-native-community/push-notification-ios](https://www.npmjs.com/package/@react-native-community/push-notification-ios) instead
  */
 class PushNotificationIOS {
+  // $FlowFixMe[unclear-type]
   _data: Object;
+  // $FlowFixMe[unclear-type]
   _alert: string | Object;
   _sound: string;
   _category: string;
@@ -276,6 +282,7 @@ class PushNotificationIOS {
    * See https://reactnative.dev/docs/pushnotificationios#getdeliverednotifications
    */
   static getDeliveredNotifications(
+    // $FlowFixMe[unclear-type]
     callback: (notifications: Array<Object>) => void,
   ): void {
     invariant(
@@ -316,6 +323,7 @@ class PushNotificationIOS {
    *
    * See https://reactnative.dev/docs/pushnotificationios#getapplicationiconbadgenumber
    */
+  // $FlowFixMe[unclear-type]
   static getApplicationIconBadgeNumber(callback: Function): void {
     invariant(
       NativePushNotificationManagerIOS,
@@ -330,6 +338,7 @@ class PushNotificationIOS {
    *
    * See https://reactnative.dev/docs/pushnotificationios#cancellocalnotification
    */
+  // $FlowFixMe[unclear-type]
   static cancelLocalNotifications(userInfo: Object): void {
     invariant(
       NativePushNotificationManagerIOS,
@@ -343,6 +352,7 @@ class PushNotificationIOS {
    *
    * See https://reactnative.dev/docs/pushnotificationios#getscheduledlocalnotifications
    */
+  // $FlowFixMe[unclear-type]
   static getScheduledLocalNotifications(callback: Function): void {
     invariant(
       NativePushNotificationManagerIOS,
@@ -359,6 +369,7 @@ class PushNotificationIOS {
    */
   static addEventListener(
     type: PushNotificationEventName,
+    // $FlowFixMe[unclear-type]
     handler: Function,
   ): void {
     invariant(
@@ -539,6 +550,7 @@ class PushNotificationIOS {
    * `getInitialNotification` is sufficient.
    *
    */
+  // $FlowFixMe[unclear-type]
   constructor(nativeNotif: Object) {
     this._data = {};
     this._remoteNotificationCompleteCallbackCalled = false;
@@ -603,6 +615,7 @@ class PushNotificationIOS {
   /**
    * An alias for `getAlert` to get the notification's main message string.
    */
+  // $FlowFixMe[unclear-type]
   getMessage(): ?string | ?Object {
     // alias because "alert" is an ambiguous name
     return this._alert;
@@ -633,6 +646,7 @@ class PushNotificationIOS {
    *
    * See https://reactnative.dev/docs/pushnotificationios#getalert
    */
+  // $FlowFixMe[unclear-type]
   getAlert(): ?string | ?Object {
     return this._alert;
   }
@@ -660,6 +674,7 @@ class PushNotificationIOS {
    *
    * See https://reactnative.dev/docs/pushnotificationios#getdata
    */
+  // $FlowFixMe[unclear-type]
   getData(): ?Object {
     return this._data;
   }
diff --git a/packages/react-native/Libraries/ReactNative/AppContainer.js b/packages/react-native/Libraries/ReactNative/AppContainer.js
index a9e6fff6541e..9c26edfd1e65 100644
--- a/packages/react-native/Libraries/ReactNative/AppContainer.js
+++ b/packages/react-native/Libraries/ReactNative/AppContainer.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -17,6 +17,7 @@ export type Props = Readonly<{
   children?: React.Node,
   rootTag: number | RootTag,
   initialProps?: {...},
+  // $FlowFixMe[unclear-type]
   WrapperComponent?: ?React.ComponentType<any>,
   rootViewStyle?: ?ViewStyleProp,
   internal_excludeLogBox?: boolean,
diff --git a/packages/react-native/Libraries/ReactNative/AppRegistry.flow.js b/packages/react-native/Libraries/ReactNative/AppRegistry.flow.js
index 94de6edde6ec..f1f5e0b58b75 100644
--- a/packages/react-native/Libraries/ReactNative/AppRegistry.flow.js
+++ b/packages/react-native/Libraries/ReactNative/AppRegistry.flow.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -13,13 +13,16 @@ import type {RootTag} from '../Types/RootTagTypes';
 import type {DisplayModeType} from './DisplayMode';
 import type {IPerformanceLogger} from './IPerformanceLogger.flow';
 
+// $FlowFixMe[unclear-type]
 type HeadlessTask = (taskData: any) => Promise<void>;
 export type TaskProvider = () => HeadlessTask;
 
+// $FlowFixMe[unclear-type]
 export type ComponentProvider = () => React.ComponentType<any>;
 export type ComponentProviderInstrumentationHook = (
   component_: ComponentProvider,
   scopedPerformanceLogger: IPerformanceLogger,
+  // $FlowFixMe[unclear-type]
 ) => React.ComponentType<any>;
 export type AppConfig = {
   appKey: string,
@@ -43,7 +46,10 @@ export type Registry = {
   ...
 };
 export type WrapperComponentProvider = (
+  // $FlowFixMe[unclear-type]
   appParameters: Object,
   appKey?: string,
+  // $FlowFixMe[unclear-type]
 ) => React.ComponentType<any>;
+// $FlowFixMe[unclear-type]
 export type RootViewStyleProvider = (appParameters: Object) => ViewStyleProp;
diff --git a/packages/react-native/Libraries/ReactNative/AppRegistry.js b/packages/react-native/Libraries/ReactNative/AppRegistry.js
index 036749c3514a..20e2168f0d62 100644
--- a/packages/react-native/Libraries/ReactNative/AppRegistry.js
+++ b/packages/react-native/Libraries/ReactNative/AppRegistry.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
diff --git a/packages/react-native/Libraries/ReactNative/AppRegistry.js.flow b/packages/react-native/Libraries/ReactNative/AppRegistry.js.flow
index aa5c650107ac..792f2c87e562 100644
--- a/packages/react-native/Libraries/ReactNative/AppRegistry.js.flow
+++ b/packages/react-native/Libraries/ReactNative/AppRegistry.js.flow
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
diff --git a/packages/react-native/Libraries/ReactNative/AppRegistryImpl.js b/packages/react-native/Libraries/ReactNative/AppRegistryImpl.js
index 33e0c84f3ba1..3166cbd5678d 100644
--- a/packages/react-native/Libraries/ReactNative/AppRegistryImpl.js
+++ b/packages/react-native/Libraries/ReactNative/AppRegistryImpl.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -113,7 +113,7 @@ export function registerComponent(
       displayMode,
     });
   };
-  if (section) {
+  if (section === true) {
     sections[appKey] = runnables[appKey];
   }
   return appKey;
@@ -220,7 +220,7 @@ export function runApplication(
  */
 export function setSurfaceProps(
   appKey: string,
-  appParameters: Object,
+  appParameters: AppParameters,
   displayMode?: number,
 ): void {
   if (appKey !== 'LogBox') {
@@ -264,7 +264,6 @@ export function registerHeadlessTask(
   taskKey: string,
   taskProvider: TaskProvider,
 ): void {
-  // $FlowFixMe[object-this-reference]
   registerCancellableHeadlessTask(taskKey, taskProvider, () => () => {
     /* Cancel is no-op */
   });
@@ -300,7 +299,7 @@ export function registerCancellableHeadlessTask(
 export function startHeadlessTask(
   taskId: number,
   taskKey: string,
-  data: any,
+  data: unknown,
 ): void {
   const NativeHeadlessJsTaskSupport =
     require('./NativeHeadlessJsTaskSupport').default;
@@ -326,8 +325,7 @@ export function startHeadlessTask(
         NativeHeadlessJsTaskSupport &&
         reason instanceof HeadlessJsTaskError
       ) {
-        // $FlowFixMe[unused-promise]
-        NativeHeadlessJsTaskSupport.notifyTaskRetry(taskId).then(
+        void NativeHeadlessJsTaskSupport.notifyTaskRetry(taskId).then(
           retryPosted => {
             if (!retryPosted) {
               NativeHeadlessJsTaskSupport.notifyTaskFinished(taskId);
diff --git a/packages/react-native/Libraries/ReactNative/BridgelessUIManager.js b/packages/react-native/Libraries/ReactNative/BridgelessUIManager.js
index 0db6d3415496..4ef402b626b3 100644
--- a/packages/react-native/Libraries/ReactNative/BridgelessUIManager.js
+++ b/packages/react-native/Libraries/ReactNative/BridgelessUIManager.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -12,27 +12,35 @@
 
 import type {RootTag} from '../Types/RootTagTypes';
 import type {UIManagerJSInterface} from '../Types/UIManagerJSInterface';
+import type {UIManagerConstants, ViewManagerConfig} from './NativeUIManager';
 
+import ReactNativeElement from '../../src/private/webapis/dom/nodes/ReactNativeElement';
 import {unstable_hasComponent} from '../NativeComponent/NativeComponentRegistryUnstable';
 import defineLazyObjectProperty from '../Utilities/defineLazyObjectProperty';
 import Platform from '../Utilities/Platform';
 import {getFabricUIManager} from './FabricUIManager';
+import {getNativeTagFromPublicInstance} from './ReactFabricPublicInstance/ReactFabricPublicInstance';
+import {
+  getNodeFromInternalInstanceHandle,
+  getPublicInstanceFromInternalInstanceHandle,
+} from './RendererImplementation';
 import nullthrows from 'nullthrows';
 
 function raiseSoftError(methodName: string, details?: string): void {
   console.error(
     `[ReactNative Architecture][JS] '${methodName}' is not available in the new React Native architecture.` +
-      (details ? ` ${details}` : ''),
+      (details != null && details !== '' ? ` ${details}` : ''),
   );
 }
 
-const getUIManagerConstants: ?() => {[viewManagerName: string]: Object} =
-  global.RN$LegacyInterop_UIManager_getConstants;
+const getUIManagerConstants: ?() => {
+  [viewManagerName: string]: ViewManagerConfig,
+} = global.RN$LegacyInterop_UIManager_getConstants;
 
 const getUIManagerConstantsCached = (function () {
   let wasCalledOnce = false;
-  let result: {[viewManagerName: string]: Object} = {};
-  return (): {[viewManagerName: string]: Object} => {
+  let result: {[viewManagerName: string]: ViewManagerConfig} = {};
+  return (): {[viewManagerName: string]: ViewManagerConfig} => {
     if (!wasCalledOnce) {
       result = nullthrows(getUIManagerConstants)();
       wasCalledOnce = true;
@@ -41,16 +49,18 @@ const getUIManagerConstantsCached = (function () {
   };
 })();
 
-const getConstantsForViewManager: ?(viewManagerName: string) => ?Object =
+const getConstantsForViewManager: ?(
+  viewManagerName: string,
+) => ?ViewManagerConfig =
   global.RN$LegacyInterop_UIManager_getConstantsForViewManager;
 
-const getDefaultEventTypes: ?() => Object =
+const getDefaultEventTypes: ?() => ViewManagerConfig =
   global.RN$LegacyInterop_UIManager_getDefaultEventTypes;
 
 const getDefaultEventTypesCached = (function () {
   let wasCalledOnce = false;
   let result = null;
-  return (): Object => {
+  return (): ViewManagerConfig => {
     if (!wasCalledOnce) {
       result = nullthrows(getDefaultEventTypes)();
       wasCalledOnce = true;
@@ -63,7 +73,13 @@ const getDefaultEventTypesCached = (function () {
  * UIManager.js overrides these APIs.
  * Pull them out from the BridgelessUIManager implementation. So, we can ignore them.
  */
-const UIManagerJSOverridenAPIs = {
+const UIManagerJSOverridenAPIs: {
+  measure: UIManagerJSInterface['measure'],
+  measureInWindow: UIManagerJSInterface['measureInWindow'],
+  measureLayout: UIManagerJSInterface['measureLayout'],
+  measureLayoutRelativeToParent: UIManagerJSInterface['measureLayoutRelativeToParent'],
+  dispatchViewManagerCommand: UIManagerJSInterface['dispatchViewManagerCommand'],
+} = {
   measure: (
     reactTag: number,
     callback: (
@@ -86,7 +102,7 @@ const UIManagerJSOverridenAPIs = {
   measureLayout: (
     reactTag: number,
     ancestorReactTag: number,
-    errorCallback: (error: Object) => void,
+    errorCallback,
     callback: (
       left: number,
       top: number,
@@ -98,7 +114,7 @@ const UIManagerJSOverridenAPIs = {
   },
   measureLayoutRelativeToParent: (
     reactTag: number,
-    errorCallback: (error: Object) => void,
+    errorCallback,
     callback: (
       left: number,
       top: number,
@@ -111,7 +127,7 @@ const UIManagerJSOverridenAPIs = {
   dispatchViewManagerCommand: (
     reactTag: number,
     commandID: number,
-    commandArgs: ?Array<string | number | boolean>,
+    commandArgs,
   ): void => {
     raiseSoftError('dispatchViewManagerCommand');
   },
@@ -122,16 +138,23 @@ const UIManagerJSOverridenAPIs = {
  * In OSS, the New Architecture will just use the Fabric renderer, which uses
  * different APIs.
  */
-const UIManagerJSUnusedInNewArchAPIs = {
+const UIManagerJSUnusedInNewArchAPIs: {
+  createView: UIManagerJSInterface['createView'],
+  updateView: UIManagerJSInterface['updateView'],
+  setChildren: UIManagerJSInterface['setChildren'],
+  manageChildren: UIManagerJSInterface['manageChildren'],
+  setJSResponder: UIManagerJSInterface['setJSResponder'],
+  clearJSResponder: UIManagerJSInterface['clearJSResponder'],
+} = {
   createView: (
     reactTag: number,
     viewName: string,
     rootTag: RootTag,
-    props: Object,
+    props,
   ): void => {
     raiseSoftError('createView');
   },
-  updateView: (reactTag: number, viewName: string, props: Object): void => {
+  updateView: (reactTag: number, viewName: string, props): void => {
     raiseSoftError('updateView');
   },
   setChildren: (containerTag: number, reactTags: Array<number>): void => {
@@ -165,7 +188,9 @@ const UIManagerJSDeprecatedPlatformAPIs = Platform.select({
 
 const UIManagerJSPlatformAPIs = Platform.select({
   android: {
-    getConstantsForViewManager: (viewManagerName: string): ?Object => {
+    getConstantsForViewManager: (
+      viewManagerName: string,
+    ): ?ViewManagerConfig => {
       if (getConstantsForViewManager) {
         return getConstantsForViewManager(viewManagerName);
       }
@@ -217,7 +242,7 @@ const UIManagerJSPlatformAPIs = Platform.select({
       const FabricUIManager = nullthrows(getFabricUIManager());
       const shadowNode =
         FabricUIManager.findShadowNodeByTag_DEPRECATED(reactTag);
-      if (!shadowNode) {
+      if (shadowNode == null) {
         console.error(
           `sendAccessibilityEvent() dropping event: Cannot find view with tag #${reactTag}`,
         );
@@ -233,7 +258,7 @@ const UIManagerJSPlatformAPIs = Platform.select({
      *
      * Leave this unimplemented until we implement lazy loading of legacy modules and view managers in the new architecture.
      */
-    lazilyLoadView: (name: string): Object => {
+    lazilyLoadView: (name: string): ViewManagerConfig => {
       raiseSoftError('lazilyLoadView');
       return {};
     },
@@ -241,7 +266,7 @@ const UIManagerJSPlatformAPIs = Platform.select({
       const FabricUIManager = nullthrows(getFabricUIManager());
       const shadowNode =
         FabricUIManager.findShadowNodeByTag_DEPRECATED(reactTag);
-      if (!shadowNode) {
+      if (shadowNode == null) {
         console.error(`focus() noop: Cannot find view with tag #${reactTag}`);
         return;
       }
@@ -251,7 +276,7 @@ const UIManagerJSPlatformAPIs = Platform.select({
       const FabricUIManager = nullthrows(getFabricUIManager());
       const shadowNode =
         FabricUIManager.findShadowNodeByTag_DEPRECATED(reactTag);
-      if (!shadowNode) {
+      if (shadowNode == null) {
         console.error(`blur() noop: Cannot find view with tag #${reactTag}`);
         return;
       }
@@ -260,12 +285,12 @@ const UIManagerJSPlatformAPIs = Platform.select({
   },
 });
 
-const UIManagerJS: UIManagerJSInterface & {[string]: any} = {
+const UIManagerJS: UIManagerJSInterface & {[string]: ViewManagerConfig} = {
   ...UIManagerJSOverridenAPIs,
   ...UIManagerJSDeprecatedPlatformAPIs,
   ...UIManagerJSPlatformAPIs,
   ...UIManagerJSUnusedInNewArchAPIs,
-  getViewManagerConfig: (viewManagerName: string): unknown => {
+  getViewManagerConfig: (viewManagerName: string): ViewManagerConfig => {
     if (getUIManagerConstants) {
       const constants = getUIManagerConstantsCached();
       if (
@@ -287,7 +312,7 @@ const UIManagerJS: UIManagerJSInterface & {[string]: any} = {
   hasViewManagerConfig: (viewManagerName: string): boolean => {
     return unstable_hasComponent(viewManagerName);
   },
-  getConstants: (): Object => {
+  getConstants: (): UIManagerConstants => {
     if (getUIManagerConstants) {
       return getUIManagerConstantsCached();
     } else {
@@ -309,7 +334,7 @@ const UIManagerJS: UIManagerJSInterface & {[string]: any} = {
     const FabricUIManager = nullthrows(getFabricUIManager());
     const shadowNode = FabricUIManager.findShadowNodeByTag_DEPRECATED(reactTag);
 
-    if (!shadowNode) {
+    if (shadowNode == null) {
       console.error(
         `findSubviewIn() noop: Cannot find view with reactTag ${reactTag}`,
       );
@@ -326,16 +351,21 @@ const UIManagerJS: UIManagerJSInterface & {[string]: any} = {
           return;
         }
 
-        let instanceHandle: Object = internalInstanceHandle;
-        let node = instanceHandle.stateNode.node;
+        const node = getNodeFromInternalInstanceHandle(internalInstanceHandle);
+        if (node == null) {
+          console.error('findSubviewIn(): Cannot find node at point');
+          return;
+        }
 
-        if (!node) {
+        const publicInstance = getPublicInstanceFromInternalInstanceHandle(
+          internalInstanceHandle,
+        );
+        if (!(publicInstance instanceof ReactNativeElement)) {
           console.error('findSubviewIn(): Cannot find node at point');
           return;
         }
 
-        let nativeViewTag: number =
-          instanceHandle.stateNode.canonical.nativeTag;
+        const nativeViewTag = getNativeTagFromPublicInstance(publicInstance);
 
         FabricUIManager.measure(
           node,
@@ -353,7 +383,7 @@ const UIManagerJS: UIManagerJSInterface & {[string]: any} = {
   ): void => {
     const FabricUIManager = nullthrows(getFabricUIManager());
     const shadowNode = FabricUIManager.findShadowNodeByTag_DEPRECATED(reactTag);
-    if (!shadowNode) {
+    if (shadowNode == null) {
       console.error(
         `viewIsDescendantOf() noop: Cannot find view with reactTag ${reactTag}`,
       );
@@ -362,7 +392,7 @@ const UIManagerJS: UIManagerJSInterface & {[string]: any} = {
 
     const ancestorShadowNode =
       FabricUIManager.findShadowNodeByTag_DEPRECATED(ancestorReactTag);
-    if (!ancestorShadowNode) {
+    if (ancestorShadowNode == null) {
       console.error(
         `viewIsDescendantOf() noop: Cannot find view with ancestorReactTag ${ancestorReactTag}`,
       );
@@ -382,11 +412,7 @@ const UIManagerJS: UIManagerJSInterface & {[string]: any} = {
 
     callback([isAncestor]);
   },
-  configureNextLayoutAnimation: (
-    config: Object,
-    callback: () => void,
-    errorCallback: (error: Object) => void,
-  ): void => {
+  configureNextLayoutAnimation: (config, callback, errorCallback): void => {
     const FabricUIManager = nullthrows(getFabricUIManager());
     FabricUIManager.configureNextLayoutAnimation(
       config,
diff --git a/packages/react-native/Libraries/ReactNative/PaperUIManager.js b/packages/react-native/Libraries/ReactNative/PaperUIManager.js
index fadf460022fd..151b06fe457c 100644
--- a/packages/react-native/Libraries/ReactNative/PaperUIManager.js
+++ b/packages/react-native/Libraries/ReactNative/PaperUIManager.js
@@ -4,12 +4,13 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
 import type {RootTag} from '../Types/RootTagTypes';
 import type {UIManagerJSInterface} from '../Types/UIManagerJSInterface';
+import type {UIManagerConstants, ViewManagerConfig} from './NativeUIManager';
 
 import NativeUIManager from './NativeUIManager';
 import nullthrows from 'nullthrows';
@@ -20,13 +21,13 @@ const defineLazyObjectProperty =
 const Platform = require('../Utilities/Platform').default;
 const UIManagerProperties = require('./UIManagerProperties').default;
 
-const viewManagerConfigs: {[string]: any | null} = {};
+const viewManagerConfigs: {[string]: ViewManagerConfig | null} = {};
 
 const triedLoadingConfig = new Set<string>();
 
 let NativeUIManagerConstants = {};
 let isNativeUIManagerConstantsSet = false;
-function getConstants(): Object {
+function getConstants(): UIManagerConstants {
   if (!isNativeUIManagerConstantsSet) {
     NativeUIManagerConstants = NativeUIManager.getConstants();
     isNativeUIManagerConstantsSet = true;
@@ -34,7 +35,7 @@ function getConstants(): Object {
   return NativeUIManagerConstants;
 }
 
-function getViewManagerConfig(viewManagerName: string): any {
+function getViewManagerConfig(viewManagerName: string): ViewManagerConfig {
   if (
     viewManagerConfigs[viewManagerName] === undefined &&
     NativeUIManager.getConstantsForViewManager
@@ -86,7 +87,7 @@ const UIManagerJS: UIManagerJSInterface = {
     reactTag: number,
     viewName: string,
     rootTag: RootTag,
-    props: Object,
+    props,
   ): void {
     if (Platform.OS === 'ios' && viewManagerConfigs[viewName] === undefined) {
       // This is necessary to force the initialization of native viewManager
@@ -96,10 +97,10 @@ const UIManagerJS: UIManagerJSInterface = {
 
     NativeUIManager.createView(reactTag, viewName, rootTag, props);
   },
-  getConstants(): Object {
+  getConstants(): UIManagerConstants {
     return getConstants();
   },
-  getViewManagerConfig(viewManagerName: string): any {
+  getViewManagerConfig(viewManagerName: string): ViewManagerConfig {
     return getViewManagerConfig(viewManagerName);
   },
   hasViewManagerConfig(viewManagerName: string): boolean {
diff --git a/packages/react-native/Libraries/ReactNative/ReactFabricPublicInstance/ReactNativeAttributePayload.js b/packages/react-native/Libraries/ReactNative/ReactFabricPublicInstance/ReactNativeAttributePayload.js
index 0f1edf031d0f..7d8f1a275fc6 100644
--- a/packages/react-native/Libraries/ReactNative/ReactFabricPublicInstance/ReactNativeAttributePayload.js
+++ b/packages/react-native/Libraries/ReactNative/ReactFabricPublicInstance/ReactNativeAttributePayload.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -24,7 +24,7 @@ const emptyObject = {};
  * across modules, I've kept them isolated to this module.
  */
 
-type NestedNode = Array<NestedNode> | Object;
+type NestedNode = Array<NestedNode> | {[string]: unknown};
 
 // Tracks removed keys
 let removedKeys: {[string]: boolean} | null = null;
@@ -45,7 +45,7 @@ function defaultDiffer(prevProp: unknown, nextProp: unknown): boolean {
 }
 
 function restoreDeletedValuesInNestedArray(
-  updatePayload: Object,
+  updatePayload: {[string]: unknown},
   node: NestedNode,
   validAttributes: AttributeConfiguration,
 ) {
@@ -76,11 +76,9 @@ function restoreDeletedValuesInNestedArray(
       }
 
       if (typeof nextProp === 'function') {
-        // $FlowFixMe[incompatible-type] found when upgrading Flow
         nextProp = true;
       }
       if (typeof nextProp === 'undefined') {
-        // $FlowFixMe[incompatible-type] found when upgrading Flow
         nextProp = null;
       }
 
@@ -106,11 +104,12 @@ function restoreDeletedValuesInNestedArray(
 }
 
 function diffNestedArrayProperty(
-  updatePayload: null | Object,
+  updatePayloadInput: null | {[string]: unknown},
   prevArray: Array<NestedNode>,
   nextArray: Array<NestedNode>,
   validAttributes: AttributeConfiguration,
-): null | Object {
+): null | {[string]: unknown} {
+  let updatePayload = updatePayloadInput;
   const minLength =
     prevArray.length < nextArray.length ? prevArray.length : nextArray.length;
   let i;
@@ -144,11 +143,11 @@ function diffNestedArrayProperty(
 }
 
 function diffNestedProperty(
-  updatePayload: null | Object,
+  updatePayload: null | {[string]: unknown},
   prevProp: NestedNode,
   nextProp: NestedNode,
   validAttributes: AttributeConfiguration,
-): null | Object {
+): null | {[string]: unknown} {
   if (!updatePayload && prevProp === nextProp) {
     // If no properties have been added, then we can bail out quickly on object
     // equality.
@@ -183,7 +182,9 @@ function diffNestedProperty(
   if (Array.isArray(prevProp)) {
     return diffProperties(
       updatePayload,
+      // $FlowFixMe[incompatible-type] flattenStyle is reused to flatten a nested style array here
       flattenStyle(prevProp),
+      // $FlowFixMe[incompatible-type] a non-array nested node is a plain props object here
       nextProp,
       validAttributes,
     );
@@ -192,6 +193,7 @@ function diffNestedProperty(
   return diffProperties(
     updatePayload,
     prevProp,
+    // $FlowFixMe[incompatible-type] flattenStyle is reused to flatten a nested style array here
     flattenStyle(nextProp),
     validAttributes,
   );
@@ -202,10 +204,11 @@ function diffNestedProperty(
  * adds a null sentinel to the updatePayload, for each prop key.
  */
 function clearNestedProperty(
-  updatePayload: null | Object,
+  updatePayloadInput: null | {[string]: unknown},
   prevProp: NestedNode,
   validAttributes: AttributeConfiguration,
-): null | Object {
+): null | {[string]: unknown} {
+  let updatePayload = updatePayloadInput;
   if (!prevProp) {
     return updatePayload;
   }
@@ -233,14 +236,15 @@ function clearNestedProperty(
  * anything changed.
  */
 function diffProperties(
-  updatePayload: null | Object,
-  prevProps: Object,
-  nextProps: Object,
+  updatePayloadInput: null | {[string]: unknown},
+  prevProps: {[string]: unknown},
+  nextProps: {[string]: unknown},
   validAttributes: AttributeConfiguration,
-): null | Object {
+): null | {[string]: unknown} {
+  let updatePayload = updatePayloadInput;
   let attributeConfig;
-  let nextProp;
-  let prevProp;
+  let nextProp: unknown;
+  let prevProp: unknown;
 
   for (const propKey in nextProps) {
     attributeConfig = validAttributes[propKey];
@@ -258,11 +262,11 @@ function diffProperties(
       if (!attributeConfigHasProcess) {
         // functions are converted to booleans as markers that the associated
         // events should be sent from native.
-        nextProp = true as any;
+        nextProp = true;
         // If nextProp is not a function, then don't bother changing prevProp
         // since nextProp will win and go into the updatePayload regardless.
         if (typeof prevProp === 'function') {
-          prevProp = true as any;
+          prevProp = true;
         }
       }
     }
@@ -270,9 +274,9 @@ function diffProperties(
     // An explicit value of undefined is treated as a null because it overrides
     // any other preceding value.
     if (typeof nextProp === 'undefined') {
-      nextProp = null as any;
+      nextProp = null;
       if (typeof prevProp === 'undefined') {
-        prevProp = null as any;
+        prevProp = null;
       }
     }
 
@@ -313,7 +317,7 @@ function diffProperties(
       // case: !Object is the default case
       if (defaultDiffer(prevProp, nextProp)) {
         // a normal leaf has changed
-        (updatePayload || (updatePayload = {} as {[string]: $FlowFixMe}))[
+        (updatePayload || (updatePayload = {} as {[string]: unknown}))[
           propKey
         ] = nextProp;
       }
@@ -333,7 +337,7 @@ function diffProperties(
             ? // $FlowFixMe[incompatible-use] found when upgrading Flow
               attributeConfig.process(nextProp)
             : nextProp;
-        (updatePayload || (updatePayload = {} as {[string]: $FlowFixMe}))[
+        (updatePayload || (updatePayload = {} as {[string]: unknown}))[
           propKey
         ] = nextValue;
       }
@@ -345,14 +349,19 @@ function diffProperties(
       // this point so we assume it must be AttributeConfiguration.
       updatePayload = diffNestedProperty(
         updatePayload,
+        // $FlowFixMe[incompatible-type] prop values are typed `unknown` but are nodes in this nested-config path
         prevProp,
+        // $FlowFixMe[incompatible-type] prop values are typed `unknown` but are nodes in this nested-config path
         nextProp,
+        // $FlowFixMe[unclear-type] AttributeConfiguration/AnyAttributeType are defined upstream with $FlowFixMe
         attributeConfig as any as AttributeConfiguration,
       );
       if (removedKeyCount > 0 && updatePayload) {
         restoreDeletedValuesInNestedArray(
           updatePayload,
+          // $FlowFixMe[incompatible-type] prop values are typed `unknown` but are nodes in this nested-config path
           nextProp,
+          // $FlowFixMe[unclear-type] AttributeConfiguration/AnyAttributeType are defined upstream with $FlowFixMe
           attributeConfig as any as AttributeConfiguration,
         );
         removedKeys = null;
@@ -389,9 +398,8 @@ function diffProperties(
     ) {
       // case: CustomAttributeConfiguration | !Object
       // Flag the leaf property for removal by sending a sentinel.
-      (updatePayload || (updatePayload = {} as {[string]: $FlowFixMe}))[
-        propKey
-      ] = null;
+      (updatePayload || (updatePayload = {} as {[string]: unknown}))[propKey] =
+        null;
       if (!removedKeys) {
         removedKeys = {} as {[string]: boolean};
       }
@@ -405,7 +413,9 @@ function diffProperties(
       // were removed so we need to go through and clear out all of them.
       updatePayload = clearNestedProperty(
         updatePayload,
+        // $FlowFixMe[incompatible-type] prop values are typed `unknown` but are nodes in this nested-config path
         prevProp,
+        // $FlowFixMe[unclear-type] AttributeConfiguration/AnyAttributeType are defined upstream with $FlowFixMe
         attributeConfig as any as AttributeConfiguration,
       );
     }
@@ -414,10 +424,11 @@ function diffProperties(
 }
 
 function addNestedProperty(
-  payload: null | Object,
-  props: Object,
+  payloadInput: null | {[string]: unknown},
+  props: NestedNode,
   validAttributes: AttributeConfiguration,
-): null | Object {
+): null | {[string]: unknown} {
+  let payload = payloadInput;
   // Flatten nested style props.
   if (Array.isArray(props)) {
     for (let i = 0; i < props.length; i++) {
@@ -431,6 +442,7 @@ function addNestedProperty(
 
     const attributeConfig = validAttributes[
       propKey
+      // $FlowFixMe[unclear-type] AttributeConfiguration/AnyAttributeType are defined upstream with $FlowFixMe
     ] as any as AttributeConfiguration;
 
     if (attributeConfig == null) {
@@ -466,13 +478,18 @@ function addNestedProperty(
 
     if (newValue !== undefined) {
       if (!payload) {
-        payload = {} as {[string]: $FlowFixMe};
+        payload = {} as {[string]: unknown};
       }
       payload[propKey] = newValue;
       continue;
     }
 
-    payload = addNestedProperty(payload, prop, attributeConfig);
+    payload = addNestedProperty(
+      payload,
+      // $FlowFixMe[incompatible-type] prop values are typed `unknown` but are nodes here
+      prop,
+      attributeConfig,
+    );
   }
 
   return payload;
@@ -483,25 +500,25 @@ function addNestedProperty(
  * to the payload for each valid key.
  */
 function clearProperties(
-  updatePayload: null | Object,
-  prevProps: Object,
+  updatePayload: null | {[string]: unknown},
+  prevProps: {[string]: unknown},
   validAttributes: AttributeConfiguration,
-): null | Object {
+): null | {[string]: unknown} {
   return diffProperties(updatePayload, prevProps, emptyObject, validAttributes);
 }
 
 export function create(
-  props: Object,
+  props: NestedNode,
   validAttributes: AttributeConfiguration,
-): null | Object {
+): null | {[string]: unknown} {
   return addNestedProperty(null, props, validAttributes);
 }
 
 export function diff(
-  prevProps: Object,
-  nextProps: Object,
+  prevProps: {[string]: unknown},
+  nextProps: {[string]: unknown},
   validAttributes: AttributeConfiguration,
-): null | Object {
+): null | {[string]: unknown} {
   return diffProperties(
     null, // updatePayload
     prevProps,
diff --git a/packages/react-native/Libraries/ReactNative/UIManager.js b/packages/react-native/Libraries/ReactNative/UIManager.js
index a97c6a7b3ea7..a020393458ab 100644
--- a/packages/react-native/Libraries/ReactNative/UIManager.js
+++ b/packages/react-native/Libraries/ReactNative/UIManager.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -60,7 +60,7 @@ const UIManager: UIManagerJSInterface = {
       const FabricUIManager = nullthrows(getFabricUIManager());
       const shadowNode =
         FabricUIManager.findShadowNodeByTag_DEPRECATED(reactTag);
-      if (shadowNode) {
+      if (shadowNode != null) {
         FabricUIManager.measure(shadowNode, callback);
       } else {
         console.warn(`measure cannot find view with tag #${reactTag}`);
@@ -103,7 +103,7 @@ const UIManager: UIManagerJSInterface = {
       const FabricUIManager = nullthrows(getFabricUIManager());
       const shadowNode =
         FabricUIManager.findShadowNodeByTag_DEPRECATED(reactTag);
-      if (shadowNode) {
+      if (shadowNode != null) {
         FabricUIManager.measureInWindow(shadowNode, callback);
       } else {
         console.warn(`measure cannot find view with tag #${reactTag}`);
@@ -129,7 +129,7 @@ const UIManager: UIManagerJSInterface = {
   measureLayout(
     reactTag: number,
     ancestorReactTag: number,
-    errorCallback: (error: Object) => void,
+    errorCallback,
     callback: (
       left: number,
       top: number,
@@ -144,7 +144,7 @@ const UIManager: UIManagerJSInterface = {
       const ancestorShadowNode =
         FabricUIManager.findShadowNodeByTag_DEPRECATED(ancestorReactTag);
 
-      if (!shadowNode || !ancestorShadowNode) {
+      if (shadowNode == null || ancestorShadowNode == null) {
         return;
       }
 
@@ -167,7 +167,7 @@ const UIManager: UIManagerJSInterface = {
 
   measureLayoutRelativeToParent(
     reactTag: number,
-    errorCallback: (error: Object) => void,
+    errorCallback,
     callback: (
       left: number,
       top: number,
@@ -182,7 +182,7 @@ const UIManager: UIManagerJSInterface = {
       const FabricUIManager = nullthrows(getFabricUIManager());
       const shadowNode =
         FabricUIManager.findShadowNodeByTag_DEPRECATED(reactTag);
-      if (shadowNode) {
+      if (shadowNode != null) {
         FabricUIManager.measure(
           shadowNode,
           (left, top, width, height, pageX, pageY) => {
@@ -210,7 +210,7 @@ const UIManager: UIManagerJSInterface = {
   dispatchViewManagerCommand(
     reactTag: number,
     commandName: number | string,
-    commandArgs: any[],
+    commandArgs: Array<unknown>,
   ) {
     // Sometimes, libraries directly pass in the output of `findNodeHandle` to
     // this function without checking if it's null. This guards against that
@@ -224,12 +224,16 @@ const UIManager: UIManagerJSInterface = {
       const FabricUIManager = nullthrows(getFabricUIManager());
       const shadowNode =
         FabricUIManager.findShadowNodeByTag_DEPRECATED(reactTag);
-      if (shadowNode) {
+      if (shadowNode != null) {
         // Transform the accidental CommandID into a CommandName which is the stringified number.
         // The interop layer knows how to convert this number into the right method name.
         // Stringify a string is a no-op, so it's safe.
-        commandName = `${commandName}`;
-        FabricUIManager.dispatchCommand(shadowNode, commandName, commandArgs);
+        const resolvedCommandName = `${commandName}`;
+        FabricUIManager.dispatchCommand(
+          shadowNode,
+          resolvedCommandName,
+          commandArgs,
+        );
       }
     } else {
       UIManagerImpl.dispatchViewManagerCommand(
diff --git a/packages/react-native/Libraries/ReactNative/getNativeComponentAttributes.js b/packages/react-native/Libraries/ReactNative/getNativeComponentAttributes.js
index 26846a19c551..c684465410c1 100644
--- a/packages/react-native/Libraries/ReactNative/getNativeComponentAttributes.js
+++ b/packages/react-native/Libraries/ReactNative/getNativeComponentAttributes.js
@@ -4,12 +4,14 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
 'use strict';
 
+import type {ViewManagerConfig} from './NativeUIManager';
+
 import processBoxShadow from '../StyleSheet/processBoxShadow';
 
 const ReactNativeStyleAttributes =
@@ -33,7 +35,9 @@ const sizesDiffer = require('../Utilities/differ/sizesDiffer').default;
 const UIManager = require('./UIManager').default;
 const nullthrows = require('nullthrows');
 
-function getNativeComponentAttributes(uiViewClassName: string): any {
+function getNativeComponentAttributes(
+  uiViewClassName: string,
+): ViewManagerConfig {
   const viewConfig = UIManager.getViewManagerConfig(uiViewClassName);
 
   if (viewConfig == null) {
@@ -109,17 +113,14 @@ function getNativeComponentAttributes(uiViewClassName: string): any {
   return viewConfig;
 }
 
-function attachDefaultEventTypes(viewConfig: any) {
+function attachDefaultEventTypes(viewConfig: ViewManagerConfig) {
   // This is supported on UIManager platforms (ex: Android),
   // as lazy view managers are not implemented for all platforms.
   // See [UIManager] for details on constants and implementations.
   const constants = UIManager.getConstants();
   if (constants.ViewManagerNames || constants.LazyViewManagersEnabled) {
     // Lazy view managers enabled.
-    viewConfig = merge(
-      viewConfig,
-      nullthrows(UIManager.getDefaultEventTypes)(),
-    );
+    merge(viewConfig, nullthrows(UIManager.getDefaultEventTypes)());
   } else {
     viewConfig.bubblingEventTypes = merge(
       viewConfig.bubblingEventTypes,
@@ -133,7 +134,10 @@ function attachDefaultEventTypes(viewConfig: any) {
 }
 
 // TODO: Figure out how to avoid all this runtime initialization cost.
-function merge(destination: ?Object, source: ?Object): ?Object {
+function merge(
+  destination: ?ViewManagerConfig,
+  source: ?ViewManagerConfig,
+): ?ViewManagerConfig {
   if (!source) {
     return destination;
   }
@@ -163,7 +167,12 @@ function merge(destination: ?Object, source: ?Object): ?Object {
 
 function getDifferForType(
   typeName: string,
-): ?(prevProp: any, nextProp: any) => boolean {
+): ?(
+  | typeof insetsDiffer
+  | typeof matricesDiffer
+  | typeof pointsDiffer
+  | typeof sizesDiffer
+) {
   switch (typeName) {
     // iOS Types
     case 'CATransform3D':
@@ -183,7 +192,19 @@ function getDifferForType(
   return null;
 }
 
-function getProcessorForType(typeName: string): ?(nextProp: any) => any {
+function getProcessorForType(
+  typeName: string,
+): ?(
+  | typeof processBackgroundImage
+  | typeof processBackgroundPosition
+  | typeof processBackgroundRepeat
+  | typeof processBackgroundSize
+  | typeof processBoxShadow
+  | typeof processColor
+  | typeof processColorArray
+  | typeof processFilter
+  | typeof resolveAssetSource
+) {
   switch (typeName) {
     // iOS Types
     case 'CGColor':
diff --git a/packages/react-native/Libraries/ReactNative/requireNativeComponent.js b/packages/react-native/Libraries/ReactNative/requireNativeComponent.js
index 96016159f59d..080380e0e86c 100644
--- a/packages/react-native/Libraries/ReactNative/requireNativeComponent.js
+++ b/packages/react-native/Libraries/ReactNative/requireNativeComponent.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -29,8 +29,10 @@ const getNativeComponentAttributes =
 const requireNativeComponent = <T extends {...}>(
   uiViewClassName: string,
 ): HostComponent<T> =>
-  createReactNativeComponentClass(uiViewClassName, () =>
-    getNativeComponentAttributes(uiViewClassName),
+  createReactNativeComponentClass(
+    uiViewClassName,
+    () => getNativeComponentAttributes(uiViewClassName),
+    // $FlowFixMe[unclear-type] createReactNativeComponentClass returns the registered view name (a string) that Fabric resolves to this host component at runtime
   ) as any as HostComponent<T>;
 
 export default requireNativeComponent;
diff --git a/packages/react-native/Libraries/Settings/Settings.ios.js b/packages/react-native/Libraries/Settings/Settings.ios.js
index 293fa9612cad..f06b80548970 100644
--- a/packages/react-native/Libraries/Settings/Settings.ios.js
+++ b/packages/react-native/Libraries/Settings/Settings.ios.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -14,6 +14,7 @@ import invariant from 'invariant';
 
 const subscriptions: Array<{
   keys: Array<string>,
+  // $FlowFixMe[unclear-type]
   callback: ?Function,
   ...
 }> = [];
@@ -27,6 +28,7 @@ const subscriptions: Array<{
  */
 const Settings = {
   _settings: (NativeSettingsManager &&
+    // $FlowFixMe[unclear-type]
     NativeSettingsManager.getConstants().settings) as any,
 
   /**
@@ -41,6 +43,7 @@ const Settings = {
    * Set one or more values by merging the provided object into the current
    * settings.
    */
+  // $FlowFixMe[unclear-type]
   set(settings: Object) {
     // $FlowFixMe[object-this-reference]
     // $FlowFixMe[unsafe-object-assign]
@@ -53,8 +56,10 @@ const Settings = {
    * whenever a watched key's value changes. Returns a `watchId` that can be
    * passed to `clearWatch` to unsubscribe.
    */
+  // $FlowFixMe[unclear-type]
   watchKeys(keys: string | Array<string>, callback: Function): number {
     if (typeof keys === 'string') {
+      // $FlowFixMe[reassign-const]
       keys = [keys];
     }
 
@@ -77,6 +82,7 @@ const Settings = {
     }
   },
 
+  // $FlowFixMe[unclear-type]
   _sendObservations(body: Object) {
     Object.keys(body).forEach(key => {
       const newValue = body[key];
diff --git a/packages/react-native/Libraries/Settings/Settings.js b/packages/react-native/Libraries/Settings/Settings.js
index b0ec5480569f..9d6e84fa2d2d 100644
--- a/packages/react-native/Libraries/Settings/Settings.js
+++ b/packages/react-native/Libraries/Settings/Settings.js
@@ -4,14 +4,16 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
 import Platform from '../Utilities/Platform';
 
 let Settings: {
+  // $FlowFixMe[unclear-type]
   get(key: string): any,
+  // $FlowFixMe[unclear-type]
   set(settings: Object): void,
   watchKeys(keys: string | Array<string>, callback: () => void): number,
   clearWatch(watchId: number): void,
diff --git a/packages/react-native/Libraries/Settings/SettingsFallback.js b/packages/react-native/Libraries/Settings/SettingsFallback.js
index bf00f04e16d6..b71f94948071 100644
--- a/packages/react-native/Libraries/Settings/SettingsFallback.js
+++ b/packages/react-native/Libraries/Settings/SettingsFallback.js
@@ -4,18 +4,20 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
 'use strict';
 
 const Settings = {
+  // $FlowFixMe[unclear-type]
   get(key: string): any {
     console.warn('Settings is not yet supported on this platform.');
     return null;
   },
 
+  // $FlowFixMe[unclear-type]
   set(settings: Object) {
     console.warn('Settings is not yet supported on this platform.');
   },
diff --git a/packages/react-native/Libraries/StyleSheet/StyleSheet.js b/packages/react-native/Libraries/StyleSheet/StyleSheet.js
index 529b9f3b6568..a6ec58a3fc9d 100644
--- a/packages/react-native/Libraries/StyleSheet/StyleSheet.js
+++ b/packages/react-native/Libraries/StyleSheet/StyleSheet.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
diff --git a/packages/react-native/Libraries/StyleSheet/StyleSheet.js.flow b/packages/react-native/Libraries/StyleSheet/StyleSheet.js.flow
index 101d782aa278..28c096e51e00 100644
--- a/packages/react-native/Libraries/StyleSheet/StyleSheet.js.flow
+++ b/packages/react-native/Libraries/StyleSheet/StyleSheet.js.flow
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
diff --git a/packages/react-native/Libraries/StyleSheet/StyleSheetExports.js.flow b/packages/react-native/Libraries/StyleSheet/StyleSheetExports.js.flow
index 2aa4ee1d3ffb..9520c8d24788 100644
--- a/packages/react-native/Libraries/StyleSheet/StyleSheetExports.js.flow
+++ b/packages/react-native/Libraries/StyleSheet/StyleSheetExports.js.flow
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -86,9 +86,9 @@ declare export const flatten: typeof flattenStyle;
  * internally to process color and transform values. You should not use this
  * unless you really know what you are doing and have exhausted other options.
  */
-declare export const setStyleAttributePreprocessor: (
+declare export const setStyleAttributePreprocessor: <T>(
   property: string,
-  process: (nextProp: any) => any,
+  process: (nextProp: T) => unknown,
 ) => void;
 
 /**
diff --git a/packages/react-native/Libraries/StyleSheet/processFilter.js b/packages/react-native/Libraries/StyleSheet/processFilter.js
index daf37ea25537..b2385c5fb6c1 100644
--- a/packages/react-native/Libraries/StyleSheet/processFilter.js
+++ b/packages/react-native/Libraries/StyleSheet/processFilter.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format strict-local
  */
 
@@ -51,13 +51,13 @@ export default function processFilter(
   }
 
   if (typeof filter === 'string') {
-    filter = filter.replace(NEWLINE_REGEX, ' ');
+    const normalizedFilter = filter.replace(NEWLINE_REGEX, ' ');
 
     // matches on functions with args and nested functions like "drop-shadow(10 10 10 rgba(0, 0, 0, 1))"
     FILTER_FUNCTION_REGEX.lastIndex = 0;
     let matches;
 
-    while ((matches = FILTER_FUNCTION_REGEX.exec(filter))) {
+    while ((matches = FILTER_FUNCTION_REGEX.exec(normalizedFilter))) {
       let filterName = matches[1].toLowerCase();
       if (filterName === 'drop-shadow') {
         const dropShadow = parseDropShadow(matches[2]);
@@ -159,7 +159,10 @@ function _getFilterAmount(filterName: string, filterArgs: unknown): ?number {
     // blur takes any positive CSS length that is not a percent. In RN
     // we currently only have DIPs, so we are not parsing units here.
     case 'blur':
-      if ((unit && unit !== 'px') || filterArgAsNumber < 0) {
+      if (
+        (unit != null && unit !== '' && unit !== 'px') ||
+        filterArgAsNumber < 0
+      ) {
         return undefined;
       }
       return filterArgAsNumber;
@@ -173,7 +176,10 @@ function _getFilterAmount(filterName: string, filterArgs: unknown): ?number {
     case 'opacity':
     case 'saturate':
     case 'sepia':
-      if ((unit && unit !== '%' && unit !== 'px') || filterArgAsNumber < 0) {
+      if (
+        (unit != null && unit !== '' && unit !== '%' && unit !== 'px') ||
+        filterArgAsNumber < 0
+      ) {
         return undefined;
       }
       if (unit === '%') {
diff --git a/packages/react-native/Libraries/StyleSheet/processTransform.js b/packages/react-native/Libraries/StyleSheet/processTransform.js
index d4371e2b7c8c..8d43a9ae2bc3 100644
--- a/packages/react-native/Libraries/StyleSheet/processTransform.js
+++ b/packages/react-native/Libraries/StyleSheet/processTransform.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -22,10 +22,13 @@ const invariant = require('invariant');
  * interface to native code.
  */
 function processTransform(
+  // $FlowFixMe[unclear-type]
   transform: Array<Object> | string,
+  // $FlowFixMe[unclear-type]
 ): Array<Object> | Array<number> {
   if (typeof transform === 'string') {
     const regex = new RegExp(/(\w+)\(([^)]+)\)/g);
+    // $FlowFixMe[unclear-type]
     const transformArray: Array<Object> = [];
     let matches;
 
@@ -39,13 +42,16 @@ function processTransform(
         transformArray.push({[key]: value});
       }
     }
+    // $FlowFixMe[reassign-const]
     transform = transformArray;
   }
 
   if (__DEV__) {
+    // $FlowFixMe[incompatible-type]
     _validateTransforms(transform);
   }
 
+  // $FlowFixMe[incompatible-type]
   return transform;
 }
 
@@ -138,6 +144,7 @@ const _getKeyAndValueFromCSSTransform: (
   }
 };
 
+// $FlowFixMe[unclear-type]
 function _validateTransforms(transform: Array<Object>): void {
   transform.forEach(transformation => {
     const keys = Object.keys(transformation);
@@ -160,10 +167,13 @@ function _validateTransforms(transform: Array<Object>): void {
 
 function _validateTransform(
   key: string,
+  // $FlowFixMe[unclear-type]
   value: any | number | string,
+  // $FlowFixMe[unclear-type]
   transformation: any,
 ) {
   invariant(
+    // $FlowFixMe[sketchy-null-mixed]
     !value.getValue,
     'You passed an Animated.Value to a normal component. ' +
       'You need to wrap that component in an Animated. For example, ' +
diff --git a/packages/react-native/Libraries/StyleSheet/processTransformOrigin.js b/packages/react-native/Libraries/StyleSheet/processTransformOrigin.js
index 5c132d92ae43..b90d3ced96e0 100644
--- a/packages/react-native/Libraries/StyleSheet/processTransformOrigin.js
+++ b/packages/react-native/Libraries/StyleSheet/processTransformOrigin.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -20,10 +20,11 @@ const INDEX_Z = 2;
 
 /* eslint-disable no-labels */
 export default function processTransformOrigin(
-  transformOrigin: Array<string | number> | string,
+  transformOriginInput: Array<string | number> | string,
 ): Array<string | number> {
-  if (typeof transformOrigin === 'string') {
-    const transformOriginString = transformOrigin;
+  let transformOrigin: Array<string | number>;
+  if (typeof transformOriginInput === 'string') {
+    const transformOriginString = transformOriginInput;
     TRANSFORM_ORIGIN_REGEX.lastIndex = 0;
     const transformOriginArray: Array<string | number> = ['50%', '50%', 0];
 
@@ -111,6 +112,8 @@ export default function processTransformOrigin(
     }
 
     transformOrigin = transformOriginArray;
+  } else {
+    transformOrigin = transformOriginInput;
   }
 
   if (__DEV__) {
diff --git a/packages/react-native/Libraries/StyleSheet/setNormalizedColorAlpha.js b/packages/react-native/Libraries/StyleSheet/setNormalizedColorAlpha.js
index b412b260a30c..975243ad9eed 100644
--- a/packages/react-native/Libraries/StyleSheet/setNormalizedColorAlpha.js
+++ b/packages/react-native/Libraries/StyleSheet/setNormalizedColorAlpha.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -17,15 +17,16 @@
  * alpha should be number between 0 and 1
  */
 function setNormalizedColorAlpha(input: number, alpha: number): number {
-  if (alpha < 0) {
-    alpha = 0;
-  } else if (alpha > 1) {
-    alpha = 1;
+  let normalizedAlpha = alpha;
+  if (normalizedAlpha < 0) {
+    normalizedAlpha = 0;
+  } else if (normalizedAlpha > 1) {
+    normalizedAlpha = 1;
   }
 
-  alpha = Math.round(alpha * 255);
+  normalizedAlpha = Math.round(normalizedAlpha * 255);
   // magic bitshift guarantees we return an unsigned int
-  return ((input & 0xffffff00) | alpha) >>> 0;
+  return ((input & 0xffffff00) | normalizedAlpha) >>> 0;
 }
 
 export default setNormalizedColorAlpha;
diff --git a/packages/react-native/Libraries/Text/TextNativeComponent.js b/packages/react-native/Libraries/Text/TextNativeComponent.js
index 11c869113337..38cf4537601a 100644
--- a/packages/react-native/Libraries/Text/TextNativeComponent.js
+++ b/packages/react-native/Libraries/Text/TextNativeComponent.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -77,23 +77,31 @@ const virtualTextViewConfig = {
 // Additional note: Our long term plan is to reduce the overhead of the <Text>
 // and <View> wrappers so that we no longer have any reason to export these APIs.
 export const NativeText: HostComponent<NativeTextProps> =
-  createReactNativeComponentClass('RCTText', () =>
-    createViewConfig(textViewConfig),
+  createReactNativeComponentClass(
+    'RCTText',
+    () => createViewConfig(textViewConfig),
+    // $FlowFixMe[unclear-type]
   ) as any;
 
 export const NativeVirtualText: HostComponent<NativeTextProps> =
+  // $FlowFixMe[sketchy-null-bool]
   !global.RN$Bridgeless && !UIManager.hasViewManagerConfig('RCTVirtualText')
     ? NativeText
-    : (createReactNativeComponentClass('RCTVirtualText', () =>
-        createViewConfig(virtualTextViewConfig),
+    : (createReactNativeComponentClass(
+        'RCTVirtualText',
+        () => createViewConfig(virtualTextViewConfig),
+        // $FlowFixMe[unclear-type]
       ) as any);
 
 export const NativeSelectableText: HostComponent<NativeTextProps> =
   enablePreparedTextLayout()
-    ? (createReactNativeComponentClass('RCTSelectableText', () =>
-        createViewConfig({
-          ...textViewConfig,
-          uiViewClassName: 'RCTSelectableText',
-        }),
+    ? (createReactNativeComponentClass(
+        'RCTSelectableText',
+        () =>
+          createViewConfig({
+            ...textViewConfig,
+            uiViewClassName: 'RCTSelectableText',
+          }),
+        // $FlowFixMe[unclear-type]
       ) as any)
     : NativeText;
diff --git a/packages/react-native/Libraries/Types/UIManagerJSInterface.js b/packages/react-native/Libraries/Types/UIManagerJSInterface.js
index 26d59a2c13c4..31a07cb1f807 100644
--- a/packages/react-native/Libraries/Types/UIManagerJSInterface.js
+++ b/packages/react-native/Libraries/Types/UIManagerJSInterface.js
@@ -4,13 +4,13 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
-import type {Spec} from '../ReactNative/NativeUIManager';
+import type {Spec, ViewManagerConfig} from '../ReactNative/NativeUIManager';
 
 export interface UIManagerJSInterface extends Spec {
-  readonly getViewManagerConfig: (viewManagerName: string) => Object;
+  readonly getViewManagerConfig: (viewManagerName: string) => ViewManagerConfig;
   readonly hasViewManagerConfig: (viewManagerName: string) => boolean;
 }
diff --git a/packages/react-native/Libraries/Utilities/BackHandler.js.flow b/packages/react-native/Libraries/Utilities/BackHandler.js.flow
index 68cc9095f5b5..4c1debea88b0 100644
--- a/packages/react-native/Libraries/Utilities/BackHandler.js.flow
+++ b/packages/react-native/Libraries/Utilities/BackHandler.js.flow
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
diff --git a/packages/react-native/Libraries/Utilities/Dimensions.js b/packages/react-native/Libraries/Utilities/Dimensions.js
index 85a6fc5dc494..6597885ac0db 100644
--- a/packages/react-native/Libraries/Utilities/Dimensions.js
+++ b/packages/react-native/Libraries/Utilities/Dimensions.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -111,6 +111,7 @@ class Dimensions {
    */
   static addEventListener(
     type: 'change',
+    // $FlowFixMe[unclear-type]
     handler: Function,
   ): EventSubscription {
     invariant(
diff --git a/packages/react-native/Libraries/Utilities/FeatureDetection.js b/packages/react-native/Libraries/Utilities/FeatureDetection.js
index 83cdd80ac4e1..3429a76f04ab 100644
--- a/packages/react-native/Libraries/Utilities/FeatureDetection.js
+++ b/packages/react-native/Libraries/Utilities/FeatureDetection.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -15,7 +15,9 @@
  * Note that a polyfill can technically fake this behavior but few does it.
  * Therefore, this is usually good enough for our purpose.
  */
-export function isNativeFunction(f: Function): boolean {
+export function isNativeFunction(
+  f: (...args: ReadonlyArray<unknown>) => unknown,
+): boolean {
   return typeof f === 'function' && f.toString().indexOf('[native code]') > -1;
 }
 
@@ -23,7 +25,10 @@ export function isNativeFunction(f: Function): boolean {
  * @return whether or not the constructor of @param {object} o is an native
  * function named with @param {string} expectedName.
  */
-export function hasNativeConstructor(o: Object, expectedName: string): boolean {
+export function hasNativeConstructor(
+  o: interface {},
+  expectedName: string,
+): boolean {
   const con = Object.getPrototypeOf(o).constructor;
   return con.name === expectedName && isNativeFunction(con);
 }
diff --git a/packages/react-native/Libraries/Utilities/ReactNativeTestTools.js b/packages/react-native/Libraries/Utilities/ReactNativeTestTools.js
index a29fed1f0efb..a2ae7e50a55a 100644
--- a/packages/react-native/Libraries/Utilities/ReactNativeTestTools.js
+++ b/packages/react-native/Libraries/Utilities/ReactNativeTestTools.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -163,6 +163,7 @@ function maximumDepthOfJSON(node: ?ReactTestRendererJSON): number {
   }
 }
 
+// $FlowFixMe[unclear-type]
 function renderAndEnforceStrictMode(element: React.Node): any {
   expectNoConsoleError();
   return renderWithStrictMode(element);
@@ -217,6 +218,7 @@ function scrollToBottom(instance: ReactTestInstance) {
 // To make error messages a little bit better, we attach a custom toString
 // implementation to a predicate
 function withMessage(fn: Predicate, message: string): Predicate {
+  // $FlowFixMe[unclear-type]
   (fn as any).toString = () => message;
   return fn;
 }
diff --git a/packages/react-native/Libraries/Utilities/codegenNativeCommands.js b/packages/react-native/Libraries/Utilities/codegenNativeCommands.js
index 4ef170fd7d2f..d163443ab6df 100644
--- a/packages/react-native/Libraries/Utilities/codegenNativeCommands.js
+++ b/packages/react-native/Libraries/Utilities/codegenNativeCommands.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -27,6 +27,7 @@ function codegenNativeCommands<T extends interface {}>(
     };
   });
 
+  // $FlowFixMe[unclear-type] - dynamic command object cannot be statically typed as the generic interface T
   return commandObj as any as T;
 }
 
diff --git a/packages/react-native/Libraries/Utilities/differ/deepDiffer.js b/packages/react-native/Libraries/Utilities/differ/deepDiffer.js
index 0f5d48cc7270..49d00d08146a 100644
--- a/packages/react-native/Libraries/Utilities/differ/deepDiffer.js
+++ b/packages/react-native/Libraries/Utilities/differ/deepDiffer.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -29,7 +29,9 @@ function unstable_setLogListeners(listeners: ?LogListeners) {
  * @returns {bool} true if different, false if equal
  */
 function deepDiffer(
+  // $FlowFixMe[unclear-type] - deepDiffer compares values of arbitrary shape
   one: any,
+  // $FlowFixMe[unclear-type] - deepDiffer compares values of arbitrary shape
   two: any,
   maxDepthOrOptions: Options | number = -1,
   maybeOptions?: Options,
diff --git a/packages/react-native/Libraries/Utilities/differ/insetsDiffer.js b/packages/react-native/Libraries/Utilities/differ/insetsDiffer.js
index 0742df32c31e..c504e64543a1 100644
--- a/packages/react-native/Libraries/Utilities/differ/insetsDiffer.js
+++ b/packages/react-native/Libraries/Utilities/differ/insetsDiffer.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -26,14 +26,14 @@ const dummyInsets = {
 };
 
 function insetsDiffer(one: Inset, two: Inset): boolean {
-  one = one || dummyInsets;
-  two = two || dummyInsets;
+  const insetOne = one || dummyInsets;
+  const insetTwo = two || dummyInsets;
   return (
-    one !== two &&
-    (one.top !== two.top ||
-      one.left !== two.left ||
-      one.right !== two.right ||
-      one.bottom !== two.bottom)
+    insetOne !== insetTwo &&
+    (insetOne.top !== insetTwo.top ||
+      insetOne.left !== insetTwo.left ||
+      insetOne.right !== insetTwo.right ||
+      insetOne.bottom !== insetTwo.bottom)
   );
 }
 
diff --git a/packages/react-native/Libraries/Utilities/differ/pointsDiffer.js b/packages/react-native/Libraries/Utilities/differ/pointsDiffer.js
index 9bf891f914e2..0c02cad24a66 100644
--- a/packages/react-native/Libraries/Utilities/differ/pointsDiffer.js
+++ b/packages/react-native/Libraries/Utilities/differ/pointsDiffer.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -19,9 +19,12 @@ type Point = {
 const dummyPoint: Point = {x: undefined, y: undefined};
 
 function pointsDiffer(one: ?Point, two: ?Point): boolean {
-  one = one || dummyPoint;
-  two = two || dummyPoint;
-  return one !== two && (one.x !== two.x || one.y !== two.y);
+  const onePoint = one ?? dummyPoint;
+  const twoPoint = two ?? dummyPoint;
+  return (
+    onePoint !== twoPoint &&
+    (onePoint.x !== twoPoint.x || onePoint.y !== twoPoint.y)
+  );
 }
 
 export default pointsDiffer;
diff --git a/packages/react-native/Libraries/Utilities/stringifyViewConfig.js b/packages/react-native/Libraries/Utilities/stringifyViewConfig.js
index 419bce0a8ba6..419de5b44902 100644
--- a/packages/react-native/Libraries/Utilities/stringifyViewConfig.js
+++ b/packages/react-native/Libraries/Utilities/stringifyViewConfig.js
@@ -4,19 +4,21 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
-export default function stringifyViewConfig(viewConfig: any): string {
-  return JSON.stringify(
-    viewConfig,
-    (key, val) => {
-      if (typeof val === 'function') {
-        return `ƒ ${val.name}`;
-      }
-      return val;
-    },
-    2,
+export default function stringifyViewConfig(viewConfig: unknown): string {
+  return (
+    JSON.stringify(
+      viewConfig,
+      (key, val) => {
+        if (typeof val === 'function') {
+          return `ƒ ${val.name}`;
+        }
+        return val;
+      },
+      2,
+    ) ?? ''
   );
 }
diff --git a/packages/react-native/Libraries/WebSocket/WebSocket.js b/packages/react-native/Libraries/WebSocket/WebSocket.js
index 6ed5630f7438..0a48672d8696 100644
--- a/packages/react-native/Libraries/WebSocket/WebSocket.js
+++ b/packages/react-native/Libraries/WebSocket/WebSocket.js
@@ -4,10 +4,12 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
+// flowlint unsafe-getters-setters:off
+
 import type {EventCallback} from '../../src/private/webapis/dom/events/EventTarget';
 import type {BlobData} from '../Blob/BlobTypes';
 import type {EventSubscription} from '../vendor/emitter/EventEmitter';
@@ -98,29 +100,29 @@ class WebSocket extends EventTarget {
   constructor(
     url: string,
     protocols: ?string | ?Array<string>,
-    options: ?{headers?: {origin?: string, ...}, ...},
+    options: ?{headers?: {origin?: string, ...}, origin?: string, ...},
   ) {
     super();
     this.url = url;
-    if (typeof protocols === 'string') {
-      protocols = [protocols];
-    }
-
-    const {headers = {}, ...unrecognized} = options || {};
+    const protocolList: ?Array<string> =
+      typeof protocols === 'string'
+        ? [protocols]
+        : Array.isArray(protocols)
+          ? protocols
+          : null;
+
+    const {headers = {}, ...unrecognized} = (options ?? {}) as {
+      headers?: {origin?: string, ...},
+      origin?: string,
+      ...
+    };
 
     // Preserve deprecated backwards compatibility for the 'origin' option
-    // $FlowFixMe[prop-missing]
     if (unrecognized && typeof unrecognized.origin === 'string') {
       console.warn(
         'Specifying `origin` as a WebSocket connection option is deprecated. Include it under `headers` instead.',
       );
-      /* $FlowFixMe[prop-missing] (>=0.54.0 site=react_native_fb,react_native_
-       * oss) This comment suppresses an error found when Flow v0.54 was
-       * deployed. To see the error delete this comment and run Flow. */
       headers.origin = unrecognized.origin;
-      /* $FlowFixMe[prop-missing] (>=0.54.0 site=react_native_fb,react_native_
-       * oss) This comment suppresses an error found when Flow v0.54 was
-       * deployed. To see the error delete this comment and run Flow. */
       delete unrecognized.origin;
     }
 
@@ -134,10 +136,6 @@ class WebSocket extends EventTarget {
       );
     }
 
-    if (!Array.isArray(protocols)) {
-      protocols = null;
-    }
-
     this._eventEmitter = new NativeEventEmitter(
       // T88715063: NativeEventEmitter only used this parameter on iOS. Now it uses it on all platforms, so this code was modified automatically to preserve its behavior
       // If you want to use the native module on other platforms, please remove this condition and test its behavior
@@ -149,7 +147,7 @@ class WebSocket extends EventTarget {
       global.__NETWORK_REPORTER__?.createDevToolsRequestId();
     NativeWebSocketModule.connect(
       url,
-      protocols,
+      protocolList,
       {headers, unstable_devToolsRequestId: devToolsRequestId},
       this._socketId,
     );
diff --git a/packages/react-native/Libraries/__flowtests__/ReactNativeTypes-flowtest.js b/packages/react-native/Libraries/__flowtests__/ReactNativeTypes-flowtest.js
index 57c5c8910737..38c0a45aac49 100644
--- a/packages/react-native/Libraries/__flowtests__/ReactNativeTypes-flowtest.js
+++ b/packages/react-native/Libraries/__flowtests__/ReactNativeTypes-flowtest.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -15,7 +15,7 @@ import * as React from 'react';
 
 function takesHostComponentInstance(instance: HostInstance | null): void {}
 
-const MyHostComponent = 'Host' as any as HostComponent<{...}>;
+declare const MyHostComponent: HostComponent<{...}>;
 
 <MyHostComponent
   ref={hostComponentRef => {
diff --git a/packages/react-native/ReactNativeApi.d.ts b/packages/react-native/ReactNativeApi.d.ts
index 24f632825a84..90ae080b97ad 100644
--- a/packages/react-native/ReactNativeApi.d.ts
+++ b/packages/react-native/ReactNativeApi.d.ts
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<d895833bed3d3c274a6647773deaa023>>
+ * @generated SignedSource<<e01f0871eae5b567561842e92851a53d>>
  *
  * This file was generated by scripts/js-api/build-types/index.js.
  */
@@ -336,8 +336,10 @@ declare const RCTNetworking_default: {
     method: string,
     trackingName: string | void,
     url: string,
-    headers: {},
-    data: RequestBody,
+    headers: {
+      [$$Key$$: string]: string
+    },
+    data: RequestBody | undefined,
     responseType: NativeResponseType,
     incrementalUpdates: boolean,
     timeout: number,
@@ -371,9 +373,9 @@ declare const sequence: typeof $$AnimatedImplementation.sequence
 declare const sequenceImpl: (
   animations: Array<CompositeAnimation>,
 ) => CompositeAnimation
-declare const setStyleAttributePreprocessor: (
+declare const setStyleAttributePreprocessor: <T>(
   property: string,
-  process: (nextProp: any) => any,
+  process: (nextProp: T) => unknown,
 ) => void
 declare const Settings: typeof Settings_default
 declare let Settings_default: {
@@ -1384,15 +1386,15 @@ declare class AnimatedTracking_default extends AnimatedNode_default {
   constructor(
     value: AnimatedValue_default,
     parent: AnimatedNode_default,
-    animationClass: any,
-    animationConfig: Object,
+    animationClass: new (...args: any[]) => Animation_default,
+    animationConfig: TrackingAnimationConfig,
     callback?: EndCallback | null | undefined,
     config?: AnimatedNodeConfig | null | undefined,
   )
   update(): void
 }
 declare class AnimatedValue_default extends AnimatedWithChildren_default {
-  addListener(callback: (value: any) => unknown): string
+  addListener(callback: (value: { value: number }) => unknown): string
   animate(
     animation: Animation_default,
     callback: EndCallback | null | undefined,
@@ -1766,7 +1768,7 @@ declare function counterEvent(eventName: EventName, value: number): void
 declare type create = typeof create
 declare type createAnimatedComponent = typeof createAnimatedComponent
 declare function createAnimatedComponent_default<
-  TInstance extends React.ComponentType<any>,
+  TInstance extends React.ComponentType<never>,
 >(
   Component: TInstance,
 ): AnimatedComponentType<
@@ -1960,7 +1962,7 @@ declare interface DrawerLayoutAndroidMethods {
     onFail?: () => void,
   ): void
   openDrawer(): void
-  setNativeProps(nativeProps: Object): void
+  setNativeProps(nativeProps: {}): void
 }
 declare type DrawerLayoutAndroidProps = Readonly<
   ViewProps & {
@@ -2913,7 +2915,7 @@ declare type LoopAnimationConfig = {
   iterations: number
   resetBeforeIteration?: boolean
 }
-declare type LooseOmit<O extends {}, K extends keyof any> = Pick<
+declare type LooseOmit<O extends {}, K extends number | string | symbol> = Pick<
   O,
   Exclude<keyof O, K>
 >
@@ -3242,7 +3244,7 @@ declare type OnAnimationDidFailCallback = () => void
 declare type OpaqueColorValue = NativeColorValue
 declare type OptionalFlatListProps<ItemT> = {
   columnWrapperStyle?: ViewStyleProp
-  extraData?: any
+  extraData?: unknown
   fadingEdgeLength?:
     | (number | undefined)
     | {
@@ -3269,7 +3271,7 @@ declare type OptionalFlatListProps<ItemT> = {
 }
 declare type OptionalPlatformSelectSpec<T> = { [key in PlatformOSType]?: T }
 declare type OptionalSectionListProps<ItemT, SectionT = DefaultSectionT> = {
-  extraData?: any
+  extraData?: unknown
   initialNumToRender?: number
   inverted?: boolean
   keyExtractor?: (item: ItemT, index: number) => string
@@ -4445,7 +4447,7 @@ declare type setStyleAttributePreprocessor =
   typeof setStyleAttributePreprocessor
 declare function setSurfaceProps(
   appKey: string,
-  appParameters: Object,
+  appParameters: AppParameters,
   displayMode?: number,
 ): void
 declare type Settings = typeof Settings
@@ -4507,9 +4509,9 @@ declare interface Spec extends TurboModule {
   readonly focus?: (reactTag: number) => void
   readonly getConstantsForViewManager?: (
     viewManagerName: string,
-  ) => Object | undefined
+  ) => undefined | ViewManagerConfig
   readonly getDefaultEventTypes?: () => Array<string>
-  readonly lazilyLoadView?: (name: string) => Object
+  readonly lazilyLoadView?: (name: string) => ViewManagerConfig
   readonly sendAccessibilityEvent?: (
     reactTag: number,
     eventType: number,
@@ -4517,20 +4519,20 @@ declare interface Spec extends TurboModule {
   readonly setLayoutAnimationEnabledExperimental?: (enabled: boolean) => void
   readonly clearJSResponder: () => void
   readonly configureNextLayoutAnimation: (
-    config: Object,
+    config: UnsafeObject,
     callback: () => void,
-    errorCallback: (error: Object) => void,
+    errorCallback: (error: UnsafeObject) => void,
   ) => void
   readonly createView: (
     reactTag: number,
     viewName: string,
     rootTag: RootTag,
-    props: Object,
+    props: UnsafeObject,
   ) => void
   readonly dispatchViewManagerCommand: (
     reactTag: number,
     commandID: number,
-    commandArgs?: Array<any>,
+    commandArgs?: Array<unknown>,
   ) => void
   readonly findSubviewIn: (
     reactTag: number,
@@ -4543,7 +4545,7 @@ declare interface Spec extends TurboModule {
       height: number,
     ) => void,
   ) => void
-  readonly getConstants: () => Object
+  readonly getConstants: () => UIManagerConstants
   readonly manageChildren: (
     containerTag: number,
     moveFromIndices: Array<number>,
@@ -4563,12 +4565,12 @@ declare interface Spec extends TurboModule {
   readonly measureLayout: (
     reactTag: number,
     ancestorReactTag: number,
-    errorCallback: (error: Object) => void,
+    errorCallback: (error: UnsafeObject) => void,
     callback: NativeMeasureLayoutOnSuccessCallback,
   ) => void
   readonly measureLayoutRelativeToParent: (
     reactTag: number,
-    errorCallback: (error: Object) => void,
+    errorCallback: (error: UnsafeObject) => void,
     callback: (
       left: number,
       top: number,
@@ -4584,7 +4586,7 @@ declare interface Spec extends TurboModule {
   readonly updateView: (
     reactTag: number,
     viewName: string,
-    props: Object,
+    props: UnsafeObject,
   ) => void
   readonly viewIsDescendantOf: (
     reactTag: number,
@@ -4643,13 +4645,13 @@ declare type StackProps = {
     | undefined
     | {
         animated: boolean
-        value: StatusBarProps["barStyle"]
+        value: StatusBarStyle
       }
   hidden:
     | undefined
     | {
         animated: boolean
-        transition: StatusBarProps["showHideTransition"]
+        transition: StatusBarAnimation
         value: boolean
       }
 }
@@ -4657,7 +4659,7 @@ declare type stagger = typeof stagger
 declare function startHeadlessTask(
   taskId: number,
   taskKey: string,
-  data: any,
+  data: unknown,
 ): void
 declare type State = {
   cellsAroundViewport: {
@@ -5336,6 +5338,11 @@ declare function trace<T>(
   fn: () => T,
   args?: EventArgs,
 ): T
+declare type TrackingAnimationConfig = Readonly<
+  AnimationConfig & {
+    toValue: AnimatedNode_default
+  }
+>
 declare type TransformsStyle = ____TransformStyle_Internal
 declare interface TurboModule extends DEPRECATED_RCTExport<void> {}
 declare namespace TurboModuleRegistry {
@@ -5350,8 +5357,9 @@ declare type TVViewPropsIOS = {
   readonly tvParallaxTiltAngle?: number
 }
 declare type UIManager = typeof UIManager
+declare type UIManagerConstants = UnsafeObject
 declare interface UIManagerJSInterface extends Spec {
-  readonly getViewManagerConfig: (viewManagerName: string) => Object
+  readonly getViewManagerConfig: (viewManagerName: string) => ViewManagerConfig
   readonly hasViewManagerConfig: (viewManagerName: string) => boolean
 }
 declare type unforkEvent = typeof unforkEvent
@@ -5497,6 +5505,7 @@ declare type ViewConfig = {
   readonly validAttributes: AttributeConfiguration
 }
 declare type ViewInstance = HostInstance
+declare type ViewManagerConfig = UnsafeObject
 declare interface ViewProps extends Readonly<
   DirectEventProps &
     GestureResponderHandlers &
@@ -5714,9 +5723,9 @@ export {
   AlertOptions, // 8a116d2a
   AlertType, // 5ab91217
   AndroidKeyboardEvent, // e03becc8
-  Animated, // 50cbe576
+  Animated, // 51ae1ed0
   AppConfig, // 35c0ca70
-  AppRegistry, // 1e8c5a00
+  AppRegistry, // 54cbc34d
   AppState, // 12012be5
   AppStateEvent, // 80f034c3
   AppStateStatus, // 447e5ef2
@@ -5728,8 +5737,8 @@ export {
   BackPressEventName, // 4620fb76
   BlurEvent, // 4ba4f941
   BoxShadowValue, // b679703f
-  Button, // bc8f6464
-  ButtonInstance, // d94b4241
+  Button, // f2435367
+  ButtonInstance, // e4d65823
   ButtonProps, // 21c5780c
   Clipboard, // 41addb89
   CodegenTypes, // ab4986cc
@@ -5748,8 +5757,8 @@ export {
   DimensionsPayload, // 653bc26c
   DisplayMetrics, // 1dc35cef
   DisplayMetricsAndroid, // 872e62eb
-  DrawerLayoutAndroid, // 7843b7b5
-  DrawerLayoutAndroidInstance, // c0694352
+  DrawerLayoutAndroid, // 58bc08bc
+  DrawerLayoutAndroidInstance, // aa243cbf
   DrawerLayoutAndroidProps, // 0c1d6155
   DrawerSlideEvent, // c4ab8fba
   DropShadowValue, // e9df2606
@@ -5766,9 +5775,9 @@ export {
   EventSubscription, // b8d084aa
   ExtendedExceptionData, // 5a6ccf5a
   FilterFunction, // bf24c0e3
-  FlatList, // e1b005c7
-  FlatListInstance, // 2d1d8e45
-  FlatListProps, // 94fa2dc7
+  FlatList, // 171059bc
+  FlatListInstance, // ead0b62b
+  FlatListProps, // 80710cf1
   FocusEvent, // 850f1517
   FontVariant, // 7c7558bb
   GestureResponderEvent, // 14d3e77a
@@ -5854,7 +5863,7 @@ export {
   NativeSyntheticEvent, // 534aaa92
   NativeTouchEvent, // 59b676df
   NativeUIEvent, // 44ac26ac
-  Networking, // bbc5be42
+  Networking, // bd182394
   OpaqueColorValue, // 25f3fa5b
   PackagerAsset, // d1c88cf4
   PanResponder, // e4df325a
@@ -5909,18 +5918,18 @@ export {
   ScrollEvent, // d7abdd0a
   ScrollResponderType, // ba188eae
   ScrollToLocationParamsType, // d7ecdad1
-  ScrollView, // 066a8597
+  ScrollView, // f1d46d64
   ScrollViewImperativeMethods, // 904c66fd
   ScrollViewInstance, // ccf4f341
-  ScrollViewProps, // b62913d1
+  ScrollViewProps, // 8434d563
   ScrollViewPropsAndroid, // 02f3df2e
   ScrollViewPropsIOS, // 807cb4f6
   ScrollViewScrollToOptions, // 3313411e
   SectionBase, // 9f13db00
-  SectionList, // ee3e7972
+  SectionList, // 22fb1f1f
   SectionListData, // 1a4de01a
-  SectionListInstance, // c9b991fe
-  SectionListProps, // 0e933318
+  SectionListInstance, // 297fe811
+  SectionListProps, // 47274631
   SectionListRenderItem, // 715b2086
   SectionListRenderItemInfo, // 4a48a922
   Separators, // 6a45f7e3
@@ -5931,13 +5940,13 @@ export {
   ShareActionSheetIOSOptions, // eff574f5
   ShareContent, // 7c627896
   ShareOptions, // 800c3a4e
-  StatusBar, // f95dbb76
+  StatusBar, // 5748d574
   StatusBarAnimation, // 7fd047e6
-  StatusBarInstance, // 416e9640
+  StatusBarInstance, // de13e4a1
   StatusBarProps, // c2a44d88
   StatusBarStyle, // 78f53eea
   StyleProp, // fa0e9b4a
-  StyleSheet, // e734acd4
+  StyleSheet, // 8f9da31a
   SubmitBehavior, // c4ddf490
   Switch, // f495bab3
   SwitchChangeEvent, // 899635b1
@@ -5973,15 +5982,15 @@ export {
   TouchableNativeFeedback, // fe739e82
   TouchableNativeFeedbackInstance, // 0877e3e4
   TouchableNativeFeedbackProps, // 1d0c2f30
-  TouchableOpacity, // fe716ffc
+  TouchableOpacity, // ade59062
   TouchableOpacityInstance, // b186055b
-  TouchableOpacityProps, // a3b32b69
+  TouchableOpacityProps, // 98f8b9b4
   TouchableWithoutFeedback, // ed159ba7
   TouchableWithoutFeedbackProps, // e613ed05
   TransformsStyle, // 65e70f18
   TurboModule, // dfe29706
   TurboModuleRegistry, // 4ace6db2
-  UIManager, // afbcdf05
+  UIManager, // 38bf2d34
   UTFSequence, // ad625158
   Vibration, // 31e4bbf8
   View, // 3e72139a
@@ -5993,10 +6002,10 @@ export {
   VirtualViewMode, // 6be59722
   VirtualizedList, // 68c7345e
   VirtualizedListInstance, // 423ee7c0
-  VirtualizedListProps, // f51f4a42
+  VirtualizedListProps, // 47c47ba6
   VirtualizedSectionList, // 9fd9cd61
   VirtualizedSectionListInstance, // 12b706d5
-  VirtualizedSectionListProps, // 8210f30a
+  VirtualizedSectionListProps, // 9775ebce
   WrapperComponentProvider, // 9ef54e61
   codegenNativeCommands, // 628a7c0a
   codegenNativeComponent, // 32a1bca6
@@ -6004,9 +6013,9 @@ export {
   processColor, // 6e877698
   registerCallableModule, // 839c8cfe
   requireNativeComponent, // aa36a6dd
-  useAnimatedColor, // a9dffd9f
-  useAnimatedValue, // 25733d13
-  useAnimatedValueXY, // 04c70878
+  useAnimatedColor, // d8b66fcd
+  useAnimatedValue, // 2386043c
+  useAnimatedValueXY, // 5b66327f
   useColorScheme, // d585efdb
   usePressability, // 782138ed
   useWindowDimensions, // bb4b683f
diff --git a/packages/react-native/src/private/devsupport/devmenu/elementinspector/BoxInspector.js b/packages/react-native/src/private/devsupport/devmenu/elementinspector/BoxInspector.js
index 59aa4c801a40..9565d23693de 100644
--- a/packages/react-native/src/private/devsupport/devmenu/elementinspector/BoxInspector.js
+++ b/packages/react-native/src/private/devsupport/devmenu/elementinspector/BoxInspector.js
@@ -61,10 +61,10 @@ type BoxContainerProps = Readonly<{
   title: string,
   titleStyle?: TextStyleProp,
   box: Readonly<{
-    top: number,
-    left: number,
-    right: number,
-    bottom: number,
+    top: number | string,
+    left: number | string,
+    right: number | string,
+    bottom: number | string,
   }>,
   children: React.Node,
 }>;
diff --git a/packages/react-native/src/private/devsupport/devmenu/elementinspector/ElementBox.js b/packages/react-native/src/private/devsupport/devmenu/elementinspector/ElementBox.js
index 08b4e9704ca0..a16c4fcec91c 100644
--- a/packages/react-native/src/private/devsupport/devmenu/elementinspector/ElementBox.js
+++ b/packages/react-native/src/private/devsupport/devmenu/elementinspector/ElementBox.js
@@ -16,8 +16,6 @@ import type {InspectedElementFrame} from './Inspector';
 import * as React from 'react';
 
 const View = require('../../../../../Libraries/Components/View/View').default;
-const flattenStyle =
-  require('../../../../../Libraries/StyleSheet/flattenStyle').default;
 const StyleSheet =
   require('../../../../../Libraries/StyleSheet/StyleSheet').default;
 const Dimensions =
@@ -31,9 +29,10 @@ type Props = Readonly<{
 }>;
 
 function ElementBox({frame, style}: Props): React.Node {
-  const flattenedStyle = flattenStyle(style) || {};
-  let margin: ?Readonly<Style> = resolveBoxStyle('margin', flattenedStyle);
-  let padding: ?Readonly<Style> = resolveBoxStyle('padding', flattenedStyle);
+  const marginBox = resolveBoxStyle('margin', style);
+  const paddingBox = resolveBoxStyle('padding', style);
+  let margin: ?ResolvedStyle = null;
+  let padding: ?ResolvedStyle = null;
 
   const frameStyle = {...frame};
   const contentStyle: {width: number, height: number} = {
@@ -41,8 +40,8 @@ function ElementBox({frame, style}: Props): React.Node {
     height: frame.height,
   };
 
-  if (margin != null) {
-    margin = resolveRelativeSizes(margin);
+  if (marginBox != null) {
+    margin = resolveRelativeSizes(marginBox);
 
     frameStyle.top -= margin.top;
     frameStyle.left -= margin.left;
@@ -63,8 +62,8 @@ function ElementBox({frame, style}: Props): React.Node {
     }
   }
 
-  if (padding != null) {
-    padding = resolveRelativeSizes(padding);
+  if (paddingBox != null) {
+    padding = resolveRelativeSizes(paddingBox);
 
     contentStyle.width -= padding.left + padding.right;
     contentStyle.height -= padding.top + padding.bottom;
@@ -97,6 +96,14 @@ const styles = StyleSheet.create({
 });
 
 type Style = {
+  top: number | string,
+  right: number | string,
+  bottom: number | string,
+  left: number | string,
+  ...
+};
+
+type ResolvedStyle = {
   top: number,
   right: number,
   bottom: number,
@@ -110,12 +117,13 @@ type Style = {
  * @param style the style to resolve
  * @return a modified copy
  */
-function resolveRelativeSizes(style: Readonly<Style>): Style {
-  let resolvedStyle = {...style};
+function resolveRelativeSizes(style: Readonly<Style>): ResolvedStyle {
+  const resolvedStyle = {...style};
   resolveSizeInPlace(resolvedStyle, 'top', 'height');
   resolveSizeInPlace(resolvedStyle, 'right', 'width');
   resolveSizeInPlace(resolvedStyle, 'bottom', 'height');
   resolveSizeInPlace(resolvedStyle, 'left', 'width');
+  // $FlowFixMe[incompatible-type] resolveSizeInPlace has converted every percentage/`auto` value to a number
   return resolvedStyle;
 }
 
diff --git a/packages/react-native/src/private/devsupport/devmenu/elementinspector/ElementProperties.js b/packages/react-native/src/private/devsupport/devmenu/elementinspector/ElementProperties.js
index 8a792894972d..dce0dd1bbd55 100644
--- a/packages/react-native/src/private/devsupport/devmenu/elementinspector/ElementProperties.js
+++ b/packages/react-native/src/private/devsupport/devmenu/elementinspector/ElementProperties.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -12,6 +12,7 @@
 
 import type {InspectorData} from '../../../../../Libraries/Renderer/shims/ReactNativeTypes';
 import type {ViewStyleProp} from '../../../../../Libraries/StyleSheet/StyleSheet';
+import type {InspectedElementFrame} from './Inspector';
 
 import * as React from 'react';
 
@@ -33,7 +34,7 @@ const StyleInspector = require('./StyleInspector').default;
 type Props = Readonly<{
   hierarchy: ?InspectorData['hierarchy'],
   style?: ?ViewStyleProp,
-  frame?: ?Object,
+  frame?: ?InspectedElementFrame,
   selection?: ?number,
   setSelection?: number => unknown,
 }>;
diff --git a/packages/react-native/src/private/devsupport/devmenu/elementinspector/Inspector.js b/packages/react-native/src/private/devsupport/devmenu/elementinspector/Inspector.js
index 58ec505cad23..752147347e1f 100644
--- a/packages/react-native/src/private/devsupport/devmenu/elementinspector/Inspector.js
+++ b/packages/react-native/src/private/devsupport/devmenu/elementinspector/Inspector.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
diff --git a/packages/react-native/src/private/devsupport/devmenu/elementinspector/InspectorOverlay.js b/packages/react-native/src/private/devsupport/devmenu/elementinspector/InspectorOverlay.js
index 56af66ecae2b..1fd20c607998 100644
--- a/packages/react-native/src/private/devsupport/devmenu/elementinspector/InspectorOverlay.js
+++ b/packages/react-native/src/private/devsupport/devmenu/elementinspector/InspectorOverlay.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
diff --git a/packages/react-native/src/private/devsupport/devmenu/elementinspector/ReactDevToolsOverlay.js b/packages/react-native/src/private/devsupport/devmenu/elementinspector/ReactDevToolsOverlay.js
index b506718ee86b..7598275ab4ed 100644
--- a/packages/react-native/src/private/devsupport/devmenu/elementinspector/ReactDevToolsOverlay.js
+++ b/packages/react-native/src/private/devsupport/devmenu/elementinspector/ReactDevToolsOverlay.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
diff --git a/packages/react-native/src/private/devsupport/devmenu/elementinspector/getInspectorDataForViewAtPoint.js b/packages/react-native/src/private/devsupport/devmenu/elementinspector/getInspectorDataForViewAtPoint.js
index b1708149036f..0bb6717fbf5d 100644
--- a/packages/react-native/src/private/devsupport/devmenu/elementinspector/getInspectorDataForViewAtPoint.js
+++ b/packages/react-native/src/private/devsupport/devmenu/elementinspector/getInspectorDataForViewAtPoint.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -19,25 +19,37 @@ export type ReactRenderer = {
       inspectedView: ?HostInstance,
       locationX: number,
       locationY: number,
-      callback: Function,
+      callback: (viewData: TouchedViewDataAtPoint) => void,
     ) => void,
     ...
   },
 };
 type AttachedRendererEventPayload = {id: number, renderer: ReactRenderer};
 
-const reactDevToolsHook = (window as any).__REACT_DEVTOOLS_GLOBAL_HOOK__;
+type ReactDevToolsHook = {
+  readonly on: (
+    eventName: string,
+    handler: (payload: AttachedRendererEventPayload) => void,
+  ) => void,
+  readonly renderers: ReadonlyMap<unknown, ReactRenderer>,
+  ...
+};
+
+const reactDevToolsHook: ?ReactDevToolsHook = (
+  window as {readonly __REACT_DEVTOOLS_GLOBAL_HOOK__?: ReactDevToolsHook, ...}
+).__REACT_DEVTOOLS_GLOBAL_HOOK__;
 invariant(
-  Boolean(reactDevToolsHook),
+  reactDevToolsHook != null,
   'getInspectorDataForViewAtPoint should not be used if React DevTools hook is not injected',
 );
 
 const renderers: Array<ReactRenderer> = Array.from(
-  (window as any).__REACT_DEVTOOLS_GLOBAL_HOOK__.renderers.values(),
+  reactDevToolsHook.renderers.values(),
 );
 
-const appendRenderer = ({renderer}: AttachedRendererEventPayload) =>
+const appendRenderer = ({renderer}: AttachedRendererEventPayload) => {
   renderers.push(renderer);
+};
 reactDevToolsHook.on('renderer', appendRenderer);
 
 function validateRenderers(): void {
diff --git a/packages/react-native/src/private/devsupport/devmenu/elementinspector/resolveBoxStyle.js b/packages/react-native/src/private/devsupport/devmenu/elementinspector/resolveBoxStyle.js
index 23ae4470f0e5..7c261090de96 100644
--- a/packages/react-native/src/private/devsupport/devmenu/elementinspector/resolveBoxStyle.js
+++ b/packages/react-native/src/private/devsupport/devmenu/elementinspector/resolveBoxStyle.js
@@ -4,14 +4,18 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
 'use strict';
 
+import type {ViewStyleProp} from '../../../../../Libraries/StyleSheet/StyleSheet';
+
 const I18nManager =
   require('../../../../../Libraries/ReactNative/I18nManager').default;
+const flattenStyle =
+  require('../../../../../Libraries/StyleSheet/flattenStyle').default;
 
 /**
  * Resolve a style property into its component parts.
@@ -25,15 +29,32 @@ const I18nManager =
  */
 function resolveBoxStyle(
   prefix: string,
-  style: Object,
+  style: ?ViewStyleProp,
 ): ?Readonly<{
-  bottom: number,
-  left: number,
-  right: number,
-  top: number,
+  bottom: number | string,
+  left: number | string,
+  right: number | string,
+  top: number | string,
 }> {
+  const flatStyle: ?Readonly<{[string]: unknown}> = flattenStyle(style);
+  if (flatStyle == null) {
+    return null;
+  }
+
+  const getStyleValue = (key: string): number | string | null => {
+    const value = flatStyle[key];
+    return typeof value === 'number' || typeof value === 'string'
+      ? value
+      : null;
+  };
+
   let hasParts = false;
-  const result = {
+  const result: {
+    bottom: number | string,
+    left: number | string,
+    right: number | string,
+    top: number | string,
+  } = {
     bottom: 0,
     left: 0,
     right: 0,
@@ -42,33 +63,34 @@ function resolveBoxStyle(
 
   // TODO: Fix issues with multiple properties affecting the same side.
 
-  const styleForAll = style[prefix];
+  const styleForAll = getStyleValue(prefix);
   if (styleForAll != null) {
-    for (const key of Object.keys(result)) {
-      result[key] = styleForAll;
-    }
+    result.bottom = styleForAll;
+    result.left = styleForAll;
+    result.right = styleForAll;
+    result.top = styleForAll;
     hasParts = true;
   }
 
-  const styleForHorizontal = style[prefix + 'Horizontal'];
+  const styleForHorizontal = getStyleValue(prefix + 'Horizontal');
   if (styleForHorizontal != null) {
     result.left = styleForHorizontal;
     result.right = styleForHorizontal;
     hasParts = true;
   } else {
-    const styleForLeft = style[prefix + 'Left'];
+    const styleForLeft = getStyleValue(prefix + 'Left');
     if (styleForLeft != null) {
       result.left = styleForLeft;
       hasParts = true;
     }
 
-    const styleForRight = style[prefix + 'Right'];
+    const styleForRight = getStyleValue(prefix + 'Right');
     if (styleForRight != null) {
       result.right = styleForRight;
       hasParts = true;
     }
 
-    const styleForEnd = style[prefix + 'End'];
+    const styleForEnd = getStyleValue(prefix + 'End');
     if (styleForEnd != null) {
       const constants = I18nManager.getConstants();
       if (constants.isRTL && constants.doLeftAndRightSwapInRTL) {
@@ -78,7 +100,7 @@ function resolveBoxStyle(
       }
       hasParts = true;
     }
-    const styleForStart = style[prefix + 'Start'];
+    const styleForStart = getStyleValue(prefix + 'Start');
     if (styleForStart != null) {
       const constants = I18nManager.getConstants();
       if (constants.isRTL && constants.doLeftAndRightSwapInRTL) {
@@ -90,19 +112,19 @@ function resolveBoxStyle(
     }
   }
 
-  const styleForVertical = style[prefix + 'Vertical'];
+  const styleForVertical = getStyleValue(prefix + 'Vertical');
   if (styleForVertical != null) {
     result.bottom = styleForVertical;
     result.top = styleForVertical;
     hasParts = true;
   } else {
-    const styleForBottom = style[prefix + 'Bottom'];
+    const styleForBottom = getStyleValue(prefix + 'Bottom');
     if (styleForBottom != null) {
       result.bottom = styleForBottom;
       hasParts = true;
     }
 
-    const styleForTop = style[prefix + 'Top'];
+    const styleForTop = getStyleValue(prefix + 'Top');
     if (styleForTop != null) {
       result.top = styleForTop;
       hasParts = true;
diff --git a/packages/react-native/src/private/devsupport/rndevtools/setUpFuseboxReactDevToolsDispatcher.js b/packages/react-native/src/private/devsupport/rndevtools/setUpFuseboxReactDevToolsDispatcher.js
index 79f7f4d7688a..ac4cbccef8d3 100644
--- a/packages/react-native/src/private/devsupport/rndevtools/setUpFuseboxReactDevToolsDispatcher.js
+++ b/packages/react-native/src/private/devsupport/rndevtools/setUpFuseboxReactDevToolsDispatcher.js
@@ -8,7 +8,7 @@
  * @format
  */
 
-type JSONValue =
+export type JSONValue =
   | string
   | number
   | boolean
diff --git a/packages/react-native/src/private/specs_DEPRECATED/modules/NativeAccessibilityManager.js b/packages/react-native/src/private/specs_DEPRECATED/modules/NativeAccessibilityManager.js
index b54a36179a1b..f30e52bc0b2f 100644
--- a/packages/react-native/src/private/specs_DEPRECATED/modules/NativeAccessibilityManager.js
+++ b/packages/react-native/src/private/specs_DEPRECATED/modules/NativeAccessibilityManager.js
@@ -4,46 +4,47 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
 import type {TurboModule} from '../../../../Libraries/TurboModule/RCTExport';
+import type {UnsafeObject} from '../../../../Libraries/Types/CodegenTypes';
 
 import * as TurboModuleRegistry from '../../../../Libraries/TurboModule/TurboModuleRegistry';
 
 export interface Spec extends TurboModule {
   readonly getCurrentBoldTextState: (
     onSuccess: (isBoldTextEnabled: boolean) => void,
-    onError: (error: Object) => void,
+    onError: (error: UnsafeObject) => void,
   ) => void;
   readonly getCurrentGrayscaleState: (
     onSuccess: (isGrayscaleEnabled: boolean) => void,
-    onError: (error: Object) => void,
+    onError: (error: UnsafeObject) => void,
   ) => void;
   readonly getCurrentInvertColorsState: (
     onSuccess: (isInvertColorsEnabled: boolean) => void,
-    onError: (error: Object) => void,
+    onError: (error: UnsafeObject) => void,
   ) => void;
   readonly getCurrentReduceMotionState: (
     onSuccess: (isReduceMotionEnabled: boolean) => void,
-    onError: (error: Object) => void,
+    onError: (error: UnsafeObject) => void,
   ) => void;
   readonly getCurrentDarkerSystemColorsState?: (
     onSuccess: (isDarkerSystemColorsEnabled: boolean) => void,
-    onError: (error: Object) => void,
+    onError: (error: UnsafeObject) => void,
   ) => void;
   readonly getCurrentPrefersCrossFadeTransitionsState?: (
     onSuccess: (prefersCrossFadeTransitions: boolean) => void,
-    onError: (error: Object) => void,
+    onError: (error: UnsafeObject) => void,
   ) => void;
   readonly getCurrentReduceTransparencyState: (
     onSuccess: (isReduceTransparencyEnabled: boolean) => void,
-    onError: (error: Object) => void,
+    onError: (error: UnsafeObject) => void,
   ) => void;
   readonly getCurrentVoiceOverState: (
     onSuccess: (isScreenReaderEnabled: boolean) => void,
-    onError: (error: Object) => void,
+    onError: (error: UnsafeObject) => void,
   ) => void;
   readonly setAccessibilityContentSizeMultipliers: (JSMultipliers: {
     readonly extraSmall?: ?number,
diff --git a/packages/react-native/src/private/specs_DEPRECATED/modules/NativeActionSheetManager.js b/packages/react-native/src/private/specs_DEPRECATED/modules/NativeActionSheetManager.js
index b4017988a264..fa0c95b497a7 100644
--- a/packages/react-native/src/private/specs_DEPRECATED/modules/NativeActionSheetManager.js
+++ b/packages/react-native/src/private/specs_DEPRECATED/modules/NativeActionSheetManager.js
@@ -4,11 +4,12 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
 import type {TurboModule} from '../../../../Libraries/TurboModule/RCTExport';
+import type {UnsafeObject} from '../../../../Libraries/Types/CodegenTypes';
 
 import * as TurboModuleRegistry from '../../../../Libraries/TurboModule/TurboModuleRegistry';
 
@@ -45,7 +46,7 @@ export interface Spec extends TurboModule {
     failureCallback: (error: {
       readonly domain: string,
       readonly code: string,
-      readonly userInfo?: ?Object,
+      readonly userInfo?: ?UnsafeObject,
       readonly message: string,
     }) => void,
     successCallback: (completed: boolean, activityType: ?string) => void,
diff --git a/packages/react-native/src/private/specs_DEPRECATED/modules/NativeAlertManager.js b/packages/react-native/src/private/specs_DEPRECATED/modules/NativeAlertManager.js
index 603984af224d..fadf832c2813 100644
--- a/packages/react-native/src/private/specs_DEPRECATED/modules/NativeAlertManager.js
+++ b/packages/react-native/src/private/specs_DEPRECATED/modules/NativeAlertManager.js
@@ -4,18 +4,19 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
 import type {TurboModule} from '../../../../Libraries/TurboModule/RCTExport';
+import type {UnsafeObject} from '../../../../Libraries/Types/CodegenTypes';
 
 import * as TurboModuleRegistry from '../../../../Libraries/TurboModule/TurboModuleRegistry';
 
 export type Args = {
   title?: string,
   message?: string,
-  buttons?: Array<Object>, // TODO(T67565166): have a better type
+  buttons?: Array<UnsafeObject>, // TODO(T67565166): have a better type
   type?: string,
   defaultValue?: string,
   cancelButtonKey?: string,
diff --git a/packages/react-native/src/private/specs_DEPRECATED/modules/NativeAnimatedModule.js b/packages/react-native/src/private/specs_DEPRECATED/modules/NativeAnimatedModule.js
index ea72f860bbd3..e8f6548167e0 100644
--- a/packages/react-native/src/private/specs_DEPRECATED/modules/NativeAnimatedModule.js
+++ b/packages/react-native/src/private/specs_DEPRECATED/modules/NativeAnimatedModule.js
@@ -4,11 +4,12 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
 import type {TurboModule} from '../../../../Libraries/TurboModule/RCTExport';
+import type {UnsafeObject} from '../../../../Libraries/Types/CodegenTypes';
 
 import shouldUseTurboAnimatedModule from '../../../../Libraries/Animated/shouldUseTurboAnimatedModule';
 import * as TurboModuleRegistry from '../../../../Libraries/TurboModule/TurboModuleRegistry';
@@ -24,8 +25,8 @@ export type EventMapping = {
 
 // The config has different keys depending on the type of the Node
 // TODO(T54896888): Make these types strict
-export type AnimatedNodeConfig = Object;
-export type AnimatingNodeConfig = Object;
+export type AnimatedNodeConfig = UnsafeObject;
+export type AnimatingNodeConfig = UnsafeObject;
 
 export interface Spec extends TurboModule {
   readonly startOperationBatch: () => void;
@@ -66,7 +67,7 @@ export interface Spec extends TurboModule {
   ) => void;
   readonly connectAnimatedNodeToShadowNodeFamily?: (
     nodeTag: number,
-    shadowNode: Object,
+    shadowNode: UnsafeObject,
   ) => void;
   readonly disconnectAnimatedNodeFromView: (
     nodeTag: number,
@@ -91,7 +92,7 @@ export interface Spec extends TurboModule {
 
   // All of the above in a batched mode
   readonly queueAndExecuteBatchedOperations?: (
-    operationsAndArgs: Array<any>,
+    operationsAndArgs: Array<unknown>,
   ) => void;
 }
 
diff --git a/packages/react-native/src/private/specs_DEPRECATED/modules/NativeAnimatedTurboModule.js b/packages/react-native/src/private/specs_DEPRECATED/modules/NativeAnimatedTurboModule.js
index f634843ce3b4..f21f673ce8e8 100644
--- a/packages/react-native/src/private/specs_DEPRECATED/modules/NativeAnimatedTurboModule.js
+++ b/packages/react-native/src/private/specs_DEPRECATED/modules/NativeAnimatedTurboModule.js
@@ -4,11 +4,12 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
 import type {TurboModule} from '../../../../Libraries/TurboModule/RCTExport';
+import type {UnsafeObject} from '../../../../Libraries/Types/CodegenTypes';
 
 import shouldUseTurboAnimatedModule from '../../../../Libraries/Animated/shouldUseTurboAnimatedModule';
 import * as TurboModuleRegistry from '../../../../Libraries/TurboModule/TurboModuleRegistry';
@@ -24,8 +25,8 @@ export type EventMapping = {
 
 // The config has different keys depending on the type of the Node
 // TODO(T54896888): Make these types strict
-export type AnimatedNodeConfig = Object;
-export type AnimatingNodeConfig = Object;
+export type AnimatedNodeConfig = UnsafeObject;
+export type AnimatingNodeConfig = UnsafeObject;
 
 export interface Spec extends TurboModule {
   readonly startOperationBatch: () => void;
@@ -87,7 +88,7 @@ export interface Spec extends TurboModule {
 
   // All of the above in a batched mode
   readonly queueAndExecuteBatchedOperations?: (
-    operationsAndArgs: Array<any>,
+    operationsAndArgs: Array<unknown>,
   ) => void;
 }
 
diff --git a/packages/react-native/src/private/specs_DEPRECATED/modules/NativeAppState.js b/packages/react-native/src/private/specs_DEPRECATED/modules/NativeAppState.js
index 85f8159ea175..60f04e5b0807 100644
--- a/packages/react-native/src/private/specs_DEPRECATED/modules/NativeAppState.js
+++ b/packages/react-native/src/private/specs_DEPRECATED/modules/NativeAppState.js
@@ -4,11 +4,12 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
 import type {TurboModule} from '../../../../Libraries/TurboModule/RCTExport';
+import type {UnsafeObject} from '../../../../Libraries/Types/CodegenTypes';
 
 import * as TurboModuleRegistry from '../../../../Libraries/TurboModule/TurboModuleRegistry';
 
@@ -22,7 +23,7 @@ export interface Spec extends TurboModule {
   readonly getConstants: () => AppStateConstants;
   readonly getCurrentAppState: (
     success: (appState: AppState) => void,
-    error: (error: Object) => void,
+    error: (error: UnsafeObject) => void,
   ) => void;
 
   // Events
diff --git a/packages/react-native/src/private/specs_DEPRECATED/modules/NativeBlobModule.js b/packages/react-native/src/private/specs_DEPRECATED/modules/NativeBlobModule.js
index 929a1cf098d2..82fa62b9a858 100644
--- a/packages/react-native/src/private/specs_DEPRECATED/modules/NativeBlobModule.js
+++ b/packages/react-native/src/private/specs_DEPRECATED/modules/NativeBlobModule.js
@@ -4,11 +4,12 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
 import type {TurboModule} from '../../../../Libraries/TurboModule/RCTExport';
+import type {UnsafeObject} from '../../../../Libraries/Types/CodegenTypes';
 
 import * as TurboModuleRegistry from '../../../../Libraries/TurboModule/TurboModuleRegistry';
 
@@ -19,8 +20,11 @@ export interface Spec extends TurboModule {
   readonly addNetworkingHandler: () => void;
   readonly addWebSocketHandler: (id: number) => void;
   readonly removeWebSocketHandler: (id: number) => void;
-  readonly sendOverSocket: (blob: Object, socketID: number) => void;
-  readonly createFromParts: (parts: Array<Object>, withId: string) => void;
+  readonly sendOverSocket: (blob: UnsafeObject, socketID: number) => void;
+  readonly createFromParts: (
+    parts: Array<UnsafeObject>,
+    withId: string,
+  ) => void;
   readonly release: (blobId: string) => void;
 }
 
@@ -46,10 +50,10 @@ if (NativeModule != null) {
     removeWebSocketHandler(id: number): void {
       NativeModule.removeWebSocketHandler(id);
     },
-    sendOverSocket(blob: Object, socketID: number): void {
+    sendOverSocket(blob: UnsafeObject, socketID: number): void {
       NativeModule.sendOverSocket(blob, socketID);
     },
-    createFromParts(parts: Array<Object>, withId: string): void {
+    createFromParts(parts: Array<UnsafeObject>, withId: string): void {
       NativeModule.createFromParts(parts, withId);
     },
     release(blobId: string): void {
diff --git a/packages/react-native/src/private/specs_DEPRECATED/modules/NativeFileReaderModule.js b/packages/react-native/src/private/specs_DEPRECATED/modules/NativeFileReaderModule.js
index 835bd532ee75..331f4007539c 100644
--- a/packages/react-native/src/private/specs_DEPRECATED/modules/NativeFileReaderModule.js
+++ b/packages/react-native/src/private/specs_DEPRECATED/modules/NativeFileReaderModule.js
@@ -4,17 +4,21 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
 import type {TurboModule} from '../../../../Libraries/TurboModule/RCTExport';
+import type {UnsafeObject} from '../../../../Libraries/Types/CodegenTypes';
 
 import * as TurboModuleRegistry from '../../../../Libraries/TurboModule/TurboModuleRegistry';
 
 export interface Spec extends TurboModule {
-  readonly readAsDataURL: (data: Object) => Promise<string>;
-  readonly readAsText: (data: Object, encoding: string) => Promise<string>;
+  readonly readAsDataURL: (data: UnsafeObject) => Promise<string>;
+  readonly readAsText: (
+    data: UnsafeObject,
+    encoding: string,
+  ) => Promise<string>;
 }
 
 export default TurboModuleRegistry.getEnforcing<Spec>(
diff --git a/packages/react-native/src/private/specs_DEPRECATED/modules/NativeImageLoaderAndroid.js b/packages/react-native/src/private/specs_DEPRECATED/modules/NativeImageLoaderAndroid.js
index dc30094b4189..cf056ca4d76f 100644
--- a/packages/react-native/src/private/specs_DEPRECATED/modules/NativeImageLoaderAndroid.js
+++ b/packages/react-native/src/private/specs_DEPRECATED/modules/NativeImageLoaderAndroid.js
@@ -4,11 +4,12 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
 import type {TurboModule} from '../../../../Libraries/TurboModule/RCTExport';
+import type {UnsafeObject} from '../../../../Libraries/Types/CodegenTypes';
 
 import * as TurboModuleRegistry from '../../../../Libraries/TurboModule/TurboModuleRegistry';
 
@@ -24,10 +25,10 @@ export interface Spec extends TurboModule {
   readonly getSize: (uri: string) => Promise<ImageSize>;
   readonly getSizeWithHeaders: (
     uri: string,
-    headers: Object,
+    headers: UnsafeObject,
   ) => Promise<ImageSize>;
   readonly prefetchImage: (uri: string, requestId: number) => Promise<boolean>;
-  readonly queryCache: (uris: Array<string>) => Promise<Object>;
+  readonly queryCache: (uris: Array<string>) => Promise<UnsafeObject>;
 }
 
 export default TurboModuleRegistry.getEnforcing<Spec>('ImageLoader') as Spec;
diff --git a/packages/react-native/src/private/specs_DEPRECATED/modules/NativeImageLoaderIOS.js b/packages/react-native/src/private/specs_DEPRECATED/modules/NativeImageLoaderIOS.js
index bdc908509ae2..6e273aaba435 100644
--- a/packages/react-native/src/private/specs_DEPRECATED/modules/NativeImageLoaderIOS.js
+++ b/packages/react-native/src/private/specs_DEPRECATED/modules/NativeImageLoaderIOS.js
@@ -4,12 +4,13 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
 import type {RootTag} from '../../../../Libraries/TurboModule/RCTExport';
 import type {TurboModule} from '../../../../Libraries/TurboModule/RCTExport';
+import type {UnsafeObject} from '../../../../Libraries/Types/CodegenTypes';
 
 import * as TurboModuleRegistry from '../../../../Libraries/TurboModule/TurboModuleRegistry';
 
@@ -19,7 +20,7 @@ export interface Spec extends TurboModule {
   readonly getSize: (uri: string) => Promise<ReadonlyArray<number>>;
   readonly getSizeWithHeaders: (
     uri: string,
-    headers: Object,
+    headers: UnsafeObject,
   ) => Promise<{
     width: number,
     height: number,
@@ -31,7 +32,7 @@ export interface Spec extends TurboModule {
     queryRootName: string,
     rootTag: RootTag,
   ) => Promise<boolean>;
-  readonly queryCache: (uris: Array<string>) => Promise<Object>;
+  readonly queryCache: (uris: Array<string>) => Promise<UnsafeObject>;
 }
 
 export default TurboModuleRegistry.getEnforcing<Spec>('ImageLoader') as Spec;
diff --git a/packages/react-native/src/private/specs_DEPRECATED/modules/NativeNetworkingAndroid.js b/packages/react-native/src/private/specs_DEPRECATED/modules/NativeNetworkingAndroid.js
index df9fec835c5e..d25b8cec42fa 100644
--- a/packages/react-native/src/private/specs_DEPRECATED/modules/NativeNetworkingAndroid.js
+++ b/packages/react-native/src/private/specs_DEPRECATED/modules/NativeNetworkingAndroid.js
@@ -4,11 +4,12 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
 import type {TurboModule} from '../../../../Libraries/TurboModule/RCTExport';
+import type {UnsafeObject} from '../../../../Libraries/Types/CodegenTypes';
 
 import * as TurboModuleRegistry from '../../../../Libraries/TurboModule/TurboModuleRegistry';
 
@@ -20,7 +21,7 @@ export interface Spec extends TurboModule {
     url: string,
     requestId: number,
     headers: Array<Header>,
-    data: Object,
+    data: UnsafeObject,
     responseType: string,
     useIncrementalUpdates: boolean,
     timeout: number,
diff --git a/packages/react-native/src/private/specs_DEPRECATED/modules/NativeNetworkingIOS.js b/packages/react-native/src/private/specs_DEPRECATED/modules/NativeNetworkingIOS.js
index 5fc56cb35bd5..0af1223daf10 100644
--- a/packages/react-native/src/private/specs_DEPRECATED/modules/NativeNetworkingIOS.js
+++ b/packages/react-native/src/private/specs_DEPRECATED/modules/NativeNetworkingIOS.js
@@ -4,11 +4,12 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
 import type {TurboModule} from '../../../../Libraries/TurboModule/RCTExport';
+import type {UnsafeObject} from '../../../../Libraries/Types/CodegenTypes';
 
 import * as TurboModuleRegistry from '../../../../Libraries/TurboModule/TurboModuleRegistry';
 
@@ -17,8 +18,8 @@ export interface Spec extends TurboModule {
     query: {
       method: string,
       url: string,
-      data: Object,
-      headers: Object,
+      data: UnsafeObject,
+      headers: UnsafeObject,
       responseType: string,
       incrementalUpdates: boolean,
       timeout: number,
diff --git a/packages/react-native/src/private/specs_DEPRECATED/modules/NativePushNotificationManagerIOS.js b/packages/react-native/src/private/specs_DEPRECATED/modules/NativePushNotificationManagerIOS.js
index ad4ed1de0529..c754130d8a55 100644
--- a/packages/react-native/src/private/specs_DEPRECATED/modules/NativePushNotificationManagerIOS.js
+++ b/packages/react-native/src/private/specs_DEPRECATED/modules/NativePushNotificationManagerIOS.js
@@ -4,11 +4,12 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
 import type {TurboModule} from '../../../../Libraries/TurboModule/RCTExport';
+import type {UnsafeObject} from '../../../../Libraries/Types/CodegenTypes';
 
 import * as TurboModuleRegistry from '../../../../Libraries/TurboModule/TurboModuleRegistry';
 
@@ -21,7 +22,7 @@ type Permissions = {
 type Notification = {
   readonly alertTitle?: ?string,
   readonly alertBody?: ?string,
-  readonly userInfo?: ?Object,
+  readonly userInfo?: ?UnsafeObject,
   /**
    * Identifier for the notification category. See the [Apple documentation](https://developer.apple.com/documentation/usernotifications/declaring_your_actionable_notification_types)
    * for more details.
@@ -85,7 +86,7 @@ export interface Spec extends TurboModule {
   readonly presentLocalNotification: (notification: Notification) => void;
   readonly scheduleLocalNotification: (notification: Notification) => void;
   readonly cancelAllLocalNotifications: () => void;
-  readonly cancelLocalNotifications: (userInfo: Object) => void;
+  readonly cancelLocalNotifications: (userInfo: UnsafeObject) => void;
   readonly getInitialNotification: () => Promise<?Notification>;
   readonly getScheduledLocalNotifications: (
     callback: (notification: Notification) => void,
diff --git a/packages/react-native/src/private/specs_DEPRECATED/modules/NativeRedBox.js b/packages/react-native/src/private/specs_DEPRECATED/modules/NativeRedBox.js
index b61cd62c78ef..af9b0469a685 100644
--- a/packages/react-native/src/private/specs_DEPRECATED/modules/NativeRedBox.js
+++ b/packages/react-native/src/private/specs_DEPRECATED/modules/NativeRedBox.js
@@ -4,16 +4,20 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
 import type {TurboModule} from '../../../../Libraries/TurboModule/RCTExport';
+import type {UnsafeObject} from '../../../../Libraries/Types/CodegenTypes';
 
 import * as TurboModuleRegistry from '../../../../Libraries/TurboModule/TurboModuleRegistry';
 
 export interface Spec extends TurboModule {
-  readonly setExtraData: (extraData: Object, forIdentifier: string) => void;
+  readonly setExtraData: (
+    extraData: UnsafeObject,
+    forIdentifier: string,
+  ) => void;
   readonly dismiss: () => void;
 }
 
diff --git a/packages/react-native/src/private/specs_DEPRECATED/modules/NativeSampleTurboModule.js b/packages/react-native/src/private/specs_DEPRECATED/modules/NativeSampleTurboModule.js
index 65ee3fe605c1..fd2893dbe965 100644
--- a/packages/react-native/src/private/specs_DEPRECATED/modules/NativeSampleTurboModule.js
+++ b/packages/react-native/src/private/specs_DEPRECATED/modules/NativeSampleTurboModule.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
@@ -46,18 +46,18 @@ export interface Spec extends TurboModule {
   readonly getEnum?: (arg: EnumInt) => EnumInt;
   readonly getNumber: (arg: number) => number;
   readonly getString: (arg: string) => string;
-  readonly getArray: (arg: Array<any>) => Array<any>;
-  readonly getObject: (arg: Object) => Object;
+  readonly getArray: (arg: Array<unknown>) => Array<unknown>;
+  readonly getObject: (arg: UnsafeObject) => UnsafeObject;
   readonly getUnsafeObject: (arg: UnsafeObject) => UnsafeObject;
   readonly getRootTag: (arg: RootTag) => RootTag;
-  readonly getValue: (x: number, y: string, z: Object) => Object;
+  readonly getValue: (x: number, y: string, z: UnsafeObject) => UnsafeObject;
   readonly getValueWithCallback: (callback: (value: string) => void) => void;
   readonly getValueWithPromise: (error: boolean) => Promise<string>;
   readonly voidFuncThrows?: () => void;
-  readonly getObjectThrows?: (arg: Object) => Object;
+  readonly getObjectThrows?: (arg: UnsafeObject) => UnsafeObject;
   readonly promiseThrows?: () => Promise<void>;
   readonly voidFuncAssert?: () => void;
-  readonly getObjectAssert?: (arg: Object) => Object;
+  readonly getObjectAssert?: (arg: UnsafeObject) => UnsafeObject;
   readonly promiseAssert?: () => Promise<void>;
 
   // Android-only
diff --git a/packages/react-native/src/private/specs_DEPRECATED/modules/NativeSettingsManager.js b/packages/react-native/src/private/specs_DEPRECATED/modules/NativeSettingsManager.js
index 5cc6c4cb1443..35159e98e0a2 100644
--- a/packages/react-native/src/private/specs_DEPRECATED/modules/NativeSettingsManager.js
+++ b/packages/react-native/src/private/specs_DEPRECATED/modules/NativeSettingsManager.js
@@ -4,19 +4,20 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
 import type {TurboModule} from '../../../../Libraries/TurboModule/RCTExport';
+import type {UnsafeObject} from '../../../../Libraries/Types/CodegenTypes';
 
 import * as TurboModuleRegistry from '../../../../Libraries/TurboModule/TurboModuleRegistry';
 
 export interface Spec extends TurboModule {
   readonly getConstants: () => {
-    settings: Object,
+    settings: UnsafeObject,
   };
-  readonly setValues: (values: Object) => void;
+  readonly setValues: (values: UnsafeObject) => void;
   readonly deleteValues: (values: Array<string>) => void;
 }
 
diff --git a/packages/react-native/src/private/specs_DEPRECATED/modules/NativeUIManager.js b/packages/react-native/src/private/specs_DEPRECATED/modules/NativeUIManager.js
index 59683ec59aec..2363c5aa96f7 100644
--- a/packages/react-native/src/private/specs_DEPRECATED/modules/NativeUIManager.js
+++ b/packages/react-native/src/private/specs_DEPRECATED/modules/NativeUIManager.js
@@ -4,15 +4,32 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
 import type {RootTag} from '../../../../Libraries/TurboModule/RCTExport';
 import type {TurboModule} from '../../../../Libraries/TurboModule/RCTExport';
+import type {UnsafeObject} from '../../../../Libraries/Types/CodegenTypes';
 
 import * as TurboModuleRegistry from '../../../../Libraries/TurboModule/TurboModuleRegistry';
 
+/**
+ * The config object for a single native view manager. It is consumed
+ * dynamically (callers read arbitrary keys such as `Commands`, `Constants`,
+ * `NativeProps`, `bubblingEventTypes`, etc.), so it is intentionally left as an
+ * open object type. Keep this in sync with the shape produced by native.
+ */
+export type ViewManagerConfig = UnsafeObject;
+
+/**
+ * The constants object returned by `UIManager.getConstants()`. It is consumed
+ * dynamically (callers read arbitrary keys such as `ViewManagerNames`,
+ * `LazyViewManagersEnabled`, per-view-manager configs, etc.), so it is
+ * intentionally left as an open object type.
+ */
+export type UIManagerConstants = UnsafeObject;
+
 export type NativeMeasureOnSuccessCallback = (
   x: number,
   y: number,
@@ -37,17 +54,17 @@ export type NativeMeasureLayoutOnSuccessCallback = (
 ) => void;
 
 export interface Spec extends TurboModule {
-  readonly getConstants: () => Object;
+  readonly getConstants: () => UIManagerConstants;
   readonly createView: (
     reactTag: number,
     viewName: string,
     rootTag: RootTag,
-    props: Object,
+    props: UnsafeObject,
   ) => void;
   readonly updateView: (
     reactTag: number,
     viewName: string,
-    props: Object,
+    props: UnsafeObject,
   ) => void;
   readonly findSubviewIn: (
     reactTag: number,
@@ -70,7 +87,7 @@ export interface Spec extends TurboModule {
   readonly dispatchViewManagerCommand: (
     reactTag: number,
     commandID: number, // number || string
-    commandArgs?: Array<any>,
+    commandArgs?: Array<unknown>,
   ) => void;
   /**
    * Determines the location on screen, width, and height of the given view and
@@ -134,12 +151,12 @@ export interface Spec extends TurboModule {
   readonly measureLayout: (
     reactTag: number,
     ancestorReactTag: number,
-    errorCallback: (error: Object) => void,
+    errorCallback: (error: UnsafeObject) => void,
     callback: NativeMeasureLayoutOnSuccessCallback,
   ) => void;
   readonly measureLayoutRelativeToParent: (
     reactTag: number,
-    errorCallback: (error: Object) => void,
+    errorCallback: (error: UnsafeObject) => void,
     callback: (
       left: number,
       top: number,
@@ -153,9 +170,9 @@ export interface Spec extends TurboModule {
   ) => void;
   readonly clearJSResponder: () => void;
   readonly configureNextLayoutAnimation: (
-    config: Object,
+    config: UnsafeObject,
     callback: () => void, // check what is returned here
-    errorCallback: (error: Object) => void,
+    errorCallback: (error: UnsafeObject) => void,
   ) => void;
   readonly setChildren: (
     containerTag: number,
@@ -171,7 +188,9 @@ export interface Spec extends TurboModule {
   ) => void;
 
   // Android only
-  readonly getConstantsForViewManager?: (viewManagerName: string) => ?Object;
+  readonly getConstantsForViewManager?: (
+    viewManagerName: string,
+  ) => ?ViewManagerConfig;
   readonly getDefaultEventTypes?: () => Array<string>;
   /**
    * Automatically animates views to their new positions when the
@@ -192,7 +211,7 @@ export interface Spec extends TurboModule {
   ) => void;
 
   // ios only
-  readonly lazilyLoadView?: (name: string) => Object; // revisit return
+  readonly lazilyLoadView?: (name: string) => ViewManagerConfig; // revisit return
   readonly focus?: (reactTag: number) => void;
   readonly blur?: (reactTag: number) => void;
 }
diff --git a/packages/react-native/src/private/specs_DEPRECATED/modules/NativeWebSocketModule.js b/packages/react-native/src/private/specs_DEPRECATED/modules/NativeWebSocketModule.js
index f6f0cd9ddfcd..8d5b9d47b3e1 100644
--- a/packages/react-native/src/private/specs_DEPRECATED/modules/NativeWebSocketModule.js
+++ b/packages/react-native/src/private/specs_DEPRECATED/modules/NativeWebSocketModule.js
@@ -4,11 +4,12 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @flow
+ * @flow strict-local
  * @format
  */
 
 import type {TurboModule} from '../../../../Libraries/TurboModule/RCTExport';
+import type {UnsafeObject} from '../../../../Libraries/Types/CodegenTypes';
 
 import * as TurboModuleRegistry from '../../../../Libraries/TurboModule/TurboModuleRegistry';
 
@@ -17,7 +18,7 @@ export interface Spec extends TurboModule {
     url: string,
     protocols: ?Array<string>,
     options: {
-      headers?: Object,
+      headers?: UnsafeObject,
       unstable_devToolsRequestId?: string,
     },
     socketID: number,
diff --git a/scripts/cxx-api/api-snapshots/ReactAppleDebugCxx.api b/scripts/cxx-api/api-snapshots/ReactAppleDebugCxx.api
index 6e4ab04a9d24..13b9098bd58d 100644
--- a/scripts/cxx-api/api-snapshots/ReactAppleDebugCxx.api
+++ b/scripts/cxx-api/api-snapshots/ReactAppleDebugCxx.api
@@ -2504,7 +2504,7 @@ protocol NativeRedBoxSpec : public NSObjectRCTBridgeModule, public RCTTurboModul
 }
 
 protocol NativeSampleTurboModuleSpec : public NSObjectRCTBridgeModule, public RCTTurboModule {
-  public virtual NSArray<id<NSObject>>* getArray:(NSArray* arg);
+  public virtual NSArray<NSDictionary*>* getArray:(NSArray* arg);
   public virtual NSDictionary* getObject:(NSDictionary* arg);
   public virtual NSDictionary* getObjectAssert:(NSDictionary* arg);
   public virtual NSDictionary* getObjectThrows:(NSDictionary* arg);
diff --git a/scripts/cxx-api/api-snapshots/ReactAppleNewarchCxx.api b/scripts/cxx-api/api-snapshots/ReactAppleNewarchCxx.api
index 02957e06c0f6..78658d135996 100644
--- a/scripts/cxx-api/api-snapshots/ReactAppleNewarchCxx.api
+++ b/scripts/cxx-api/api-snapshots/ReactAppleNewarchCxx.api
@@ -2493,7 +2493,7 @@ protocol NativeRedBoxSpec : public NSObjectRCTBridgeModule, public RCTTurboModul
 }
 
 protocol NativeSampleTurboModuleSpec : public NSObjectRCTBridgeModule, public RCTTurboModule {
-  public virtual NSArray<id<NSObject>>* getArray:(NSArray* arg);
+  public virtual NSArray<NSDictionary*>* getArray:(NSArray* arg);
   public virtual NSDictionary* getObject:(NSDictionary* arg);
   public virtual NSDictionary* getObjectAssert:(NSDictionary* arg);
   public virtual NSDictionary* getObjectThrows:(NSDictionary* arg);
diff --git a/scripts/cxx-api/api-snapshots/ReactAppleReleaseCxx.api b/scripts/cxx-api/api-snapshots/ReactAppleReleaseCxx.api
index 94953681427d..87fcd01c36fd 100644
--- a/scripts/cxx-api/api-snapshots/ReactAppleReleaseCxx.api
+++ b/scripts/cxx-api/api-snapshots/ReactAppleReleaseCxx.api
@@ -2504,7 +2504,7 @@ protocol NativeRedBoxSpec : public NSObjectRCTBridgeModule, public RCTTurboModul
 }
 
 protocol NativeSampleTurboModuleSpec : public NSObjectRCTBridgeModule, public RCTTurboModule {
-  public virtual NSArray<id<NSObject>>* getArray:(NSArray* arg);
+  public virtual NSArray<NSDictionary*>* getArray:(NSArray* arg);
   public virtual NSDictionary* getObject:(NSDictionary* arg);
   public virtual NSDictionary* getObjectAssert:(NSDictionary* arg);
   public virtual NSDictionary* getObjectThrows:(NSDictionary* arg);