diff --git a/packages/react-reconciler/src/ReactFiber.new.js b/packages/react-reconciler/src/ReactFiber.new.js
index f5da9baa7e276..dbd7678cc5626 100644
--- a/packages/react-reconciler/src/ReactFiber.new.js
+++ b/packages/react-reconciler/src/ReactFiber.new.js
@@ -30,7 +30,6 @@ import {
 import {
   createRootStrictEffectsByDefault,
   enableCache,
-  enableStrictEffects,
   enableProfilerTimer,
   enableScopeAPI,
   enableLegacyHidden,
@@ -449,13 +448,7 @@ export function createHostRootFiber(
   let mode;
   if (tag === ConcurrentRoot) {
     mode = ConcurrentMode;
-    if (isStrictMode === true) {
-      mode |= StrictLegacyMode;
-
-      if (enableStrictEffects) {
-        mode |= StrictEffectsMode;
-      }
-    } else if (enableStrictEffects && createRootStrictEffectsByDefault) {
+    if (isStrictMode === true || createRootStrictEffectsByDefault) {
       mode |= StrictLegacyMode | StrictEffectsMode;
     }
     if (
@@ -531,7 +524,7 @@ export function createFiberFromTypeAndProps(
       case REACT_STRICT_MODE_TYPE:
         fiberTag = Mode;
         mode |= StrictLegacyMode;
-        if (enableStrictEffects && (mode & ConcurrentMode) !== NoMode) {
+        if ((mode & ConcurrentMode) !== NoMode) {
           // Strict effects should never run on legacy roots
           mode |= StrictEffectsMode;
         }
diff --git a/packages/react-reconciler/src/ReactFiber.old.js b/packages/react-reconciler/src/ReactFiber.old.js
index b7ab182a59eb5..e2905bba29f6e 100644
--- a/packages/react-reconciler/src/ReactFiber.old.js
+++ b/packages/react-reconciler/src/ReactFiber.old.js
@@ -30,7 +30,6 @@ import {
 import {
   createRootStrictEffectsByDefault,
   enableCache,
-  enableStrictEffects,
   enableProfilerTimer,
   enableScopeAPI,
   enableLegacyHidden,
@@ -449,13 +448,7 @@ export function createHostRootFiber(
   let mode;
   if (tag === ConcurrentRoot) {
     mode = ConcurrentMode;
-    if (isStrictMode === true) {
-      mode |= StrictLegacyMode;
-
-      if (enableStrictEffects) {
-        mode |= StrictEffectsMode;
-      }
-    } else if (enableStrictEffects && createRootStrictEffectsByDefault) {
+    if (isStrictMode === true || createRootStrictEffectsByDefault) {
       mode |= StrictLegacyMode | StrictEffectsMode;
     }
     if (
@@ -531,7 +524,7 @@ export function createFiberFromTypeAndProps(
       case REACT_STRICT_MODE_TYPE:
         fiberTag = Mode;
         mode |= StrictLegacyMode;
-        if (enableStrictEffects && (mode & ConcurrentMode) !== NoMode) {
+        if ((mode & ConcurrentMode) !== NoMode) {
           // Strict effects should never run on legacy roots
           mode |= StrictEffectsMode;
         }
diff --git a/packages/react-reconciler/src/ReactFiberClassComponent.new.js b/packages/react-reconciler/src/ReactFiberClassComponent.new.js
index e71ce096e3f34..f04422856e368 100644
--- a/packages/react-reconciler/src/ReactFiberClassComponent.new.js
+++ b/packages/react-reconciler/src/ReactFiberClassComponent.new.js
@@ -26,7 +26,6 @@ import {
   enableSchedulingProfiler,
   warnAboutDeprecatedLifecycles,
   enableLazyContextPropagation,
-  enableStrictEffects,
 } from 'shared/ReactFeatureFlags';
 import ReactStrictModeWarnings from './ReactStrictModeWarnings.new';
 import {isMounted} from './ReactFiberTreeReflection';
@@ -908,11 +907,7 @@ function mountClassInstance(
 
   if (typeof instance.componentDidMount === 'function') {
     let fiberFlags: Flags = Update | LayoutStatic;
-    if (
-      __DEV__ &&
-      enableStrictEffects &&
-      (workInProgress.mode & StrictEffectsMode) !== NoMode
-    ) {
+    if (__DEV__ && (workInProgress.mode & StrictEffectsMode) !== NoMode) {
       fiberFlags |= MountLayoutDev;
     }
     workInProgress.flags |= fiberFlags;
@@ -986,11 +981,7 @@ function resumeMountClassInstance(
     // effect even though we're bailing out, so that cWU/cDU are called.
     if (typeof instance.componentDidMount === 'function') {
       let fiberFlags: Flags = Update | LayoutStatic;
-      if (
-        __DEV__ &&
-        enableStrictEffects &&
-        (workInProgress.mode & StrictEffectsMode) !== NoMode
-      ) {
+      if (__DEV__ && (workInProgress.mode & StrictEffectsMode) !== NoMode) {
         fiberFlags |= MountLayoutDev;
       }
       workInProgress.flags |= fiberFlags;
@@ -1037,11 +1028,7 @@ function resumeMountClassInstance(
     }
     if (typeof instance.componentDidMount === 'function') {
       let fiberFlags: Flags = Update | LayoutStatic;
-      if (
-        __DEV__ &&
-        enableStrictEffects &&
-        (workInProgress.mode & StrictEffectsMode) !== NoMode
-      ) {
+      if (__DEV__ && (workInProgress.mode & StrictEffectsMode) !== NoMode) {
         fiberFlags |= MountLayoutDev;
       }
       workInProgress.flags |= fiberFlags;
@@ -1051,11 +1038,7 @@ function resumeMountClassInstance(
     // effect even though we're bailing out, so that cWU/cDU are called.
     if (typeof instance.componentDidMount === 'function') {
       let fiberFlags: Flags = Update | LayoutStatic;
-      if (
-        __DEV__ &&
-        enableStrictEffects &&
-        (workInProgress.mode & StrictEffectsMode) !== NoMode
-      ) {
+      if (__DEV__ && (workInProgress.mode & StrictEffectsMode) !== NoMode) {
         fiberFlags |= MountLayoutDev;
       }
       workInProgress.flags |= fiberFlags;
diff --git a/packages/react-reconciler/src/ReactFiberClassComponent.old.js b/packages/react-reconciler/src/ReactFiberClassComponent.old.js
index 9fd757eef9807..ffc7b542a6c19 100644
--- a/packages/react-reconciler/src/ReactFiberClassComponent.old.js
+++ b/packages/react-reconciler/src/ReactFiberClassComponent.old.js
@@ -26,7 +26,6 @@ import {
   enableSchedulingProfiler,
   warnAboutDeprecatedLifecycles,
   enableLazyContextPropagation,
-  enableStrictEffects,
 } from 'shared/ReactFeatureFlags';
 import ReactStrictModeWarnings from './ReactStrictModeWarnings.old';
 import {isMounted} from './ReactFiberTreeReflection';
@@ -908,11 +907,7 @@ function mountClassInstance(
 
   if (typeof instance.componentDidMount === 'function') {
     let fiberFlags: Flags = Update | LayoutStatic;
-    if (
-      __DEV__ &&
-      enableStrictEffects &&
-      (workInProgress.mode & StrictEffectsMode) !== NoMode
-    ) {
+    if (__DEV__ && (workInProgress.mode & StrictEffectsMode) !== NoMode) {
       fiberFlags |= MountLayoutDev;
     }
     workInProgress.flags |= fiberFlags;
@@ -986,11 +981,7 @@ function resumeMountClassInstance(
     // effect even though we're bailing out, so that cWU/cDU are called.
     if (typeof instance.componentDidMount === 'function') {
       let fiberFlags: Flags = Update | LayoutStatic;
-      if (
-        __DEV__ &&
-        enableStrictEffects &&
-        (workInProgress.mode & StrictEffectsMode) !== NoMode
-      ) {
+      if (__DEV__ && (workInProgress.mode & StrictEffectsMode) !== NoMode) {
         fiberFlags |= MountLayoutDev;
       }
       workInProgress.flags |= fiberFlags;
@@ -1037,11 +1028,7 @@ function resumeMountClassInstance(
     }
     if (typeof instance.componentDidMount === 'function') {
       let fiberFlags: Flags = Update | LayoutStatic;
-      if (
-        __DEV__ &&
-        enableStrictEffects &&
-        (workInProgress.mode & StrictEffectsMode) !== NoMode
-      ) {
+      if (__DEV__ && (workInProgress.mode & StrictEffectsMode) !== NoMode) {
         fiberFlags |= MountLayoutDev;
       }
       workInProgress.flags |= fiberFlags;
@@ -1051,11 +1038,7 @@ function resumeMountClassInstance(
     // effect even though we're bailing out, so that cWU/cDU are called.
     if (typeof instance.componentDidMount === 'function') {
       let fiberFlags: Flags = Update | LayoutStatic;
-      if (
-        __DEV__ &&
-        enableStrictEffects &&
-        (workInProgress.mode & StrictEffectsMode) !== NoMode
-      ) {
+      if (__DEV__ && (workInProgress.mode & StrictEffectsMode) !== NoMode) {
         fiberFlags |= MountLayoutDev;
       }
       workInProgress.flags |= fiberFlags;
diff --git a/packages/react-reconciler/src/ReactFiberCommitWork.new.js b/packages/react-reconciler/src/ReactFiberCommitWork.new.js
index ca642dcd36021..ea8e0cf26354b 100644
--- a/packages/react-reconciler/src/ReactFiberCommitWork.new.js
+++ b/packages/react-reconciler/src/ReactFiberCommitWork.new.js
@@ -54,7 +54,6 @@ import {
   enableCache,
   enableTransitionTracing,
   enableUseEventHook,
-  enableStrictEffects,
   enableFloat,
   enableLegacyHidden,
   enableHostSingletons,
@@ -4350,7 +4349,7 @@ function commitPassiveUnmountInsideDeletedTreeOnFiber(
 }
 
 function invokeLayoutEffectMountInDEV(fiber: Fiber): void {
-  if (__DEV__ && enableStrictEffects) {
+  if (__DEV__) {
     // We don't need to re-check StrictEffectsMode here.
     // This function is only called if that check has already passed.
     switch (fiber.tag) {
@@ -4378,7 +4377,7 @@ function invokeLayoutEffectMountInDEV(fiber: Fiber): void {
 }
 
 function invokePassiveEffectMountInDEV(fiber: Fiber): void {
-  if (__DEV__ && enableStrictEffects) {
+  if (__DEV__) {
     // We don't need to re-check StrictEffectsMode here.
     // This function is only called if that check has already passed.
     switch (fiber.tag) {
@@ -4397,7 +4396,7 @@ function invokePassiveEffectMountInDEV(fiber: Fiber): void {
 }
 
 function invokeLayoutEffectUnmountInDEV(fiber: Fiber): void {
-  if (__DEV__ && enableStrictEffects) {
+  if (__DEV__) {
     // We don't need to re-check StrictEffectsMode here.
     // This function is only called if that check has already passed.
     switch (fiber.tag) {
@@ -4427,7 +4426,7 @@ function invokeLayoutEffectUnmountInDEV(fiber: Fiber): void {
 }
 
 function invokePassiveEffectUnmountInDEV(fiber: Fiber): void {
-  if (__DEV__ && enableStrictEffects) {
+  if (__DEV__) {
     // We don't need to re-check StrictEffectsMode here.
     // This function is only called if that check has already passed.
     switch (fiber.tag) {
diff --git a/packages/react-reconciler/src/ReactFiberCommitWork.old.js b/packages/react-reconciler/src/ReactFiberCommitWork.old.js
index 6ba8457290910..b33a051ee09d0 100644
--- a/packages/react-reconciler/src/ReactFiberCommitWork.old.js
+++ b/packages/react-reconciler/src/ReactFiberCommitWork.old.js
@@ -54,7 +54,6 @@ import {
   enableCache,
   enableTransitionTracing,
   enableUseEventHook,
-  enableStrictEffects,
   enableFloat,
   enableLegacyHidden,
   enableHostSingletons,
@@ -4350,7 +4349,7 @@ function commitPassiveUnmountInsideDeletedTreeOnFiber(
 }
 
 function invokeLayoutEffectMountInDEV(fiber: Fiber): void {
-  if (__DEV__ && enableStrictEffects) {
+  if (__DEV__) {
     // We don't need to re-check StrictEffectsMode here.
     // This function is only called if that check has already passed.
     switch (fiber.tag) {
@@ -4378,7 +4377,7 @@ function invokeLayoutEffectMountInDEV(fiber: Fiber): void {
 }
 
 function invokePassiveEffectMountInDEV(fiber: Fiber): void {
-  if (__DEV__ && enableStrictEffects) {
+  if (__DEV__) {
     // We don't need to re-check StrictEffectsMode here.
     // This function is only called if that check has already passed.
     switch (fiber.tag) {
@@ -4397,7 +4396,7 @@ function invokePassiveEffectMountInDEV(fiber: Fiber): void {
 }
 
 function invokeLayoutEffectUnmountInDEV(fiber: Fiber): void {
-  if (__DEV__ && enableStrictEffects) {
+  if (__DEV__) {
     // We don't need to re-check StrictEffectsMode here.
     // This function is only called if that check has already passed.
     switch (fiber.tag) {
@@ -4427,7 +4426,7 @@ function invokeLayoutEffectUnmountInDEV(fiber: Fiber): void {
 }
 
 function invokePassiveEffectUnmountInDEV(fiber: Fiber): void {
-  if (__DEV__ && enableStrictEffects) {
+  if (__DEV__) {
     // We don't need to re-check StrictEffectsMode here.
     // This function is only called if that check has already passed.
     switch (fiber.tag) {
diff --git a/packages/react-reconciler/src/ReactFiberHooks.new.js b/packages/react-reconciler/src/ReactFiberHooks.new.js
index 244c0f77c6ed6..8183ddd1557c0 100644
--- a/packages/react-reconciler/src/ReactFiberHooks.new.js
+++ b/packages/react-reconciler/src/ReactFiberHooks.new.js
@@ -41,7 +41,6 @@ import {
   enableUseHook,
   enableUseMemoCacheHook,
   enableUseEventHook,
-  enableStrictEffects,
 } from 'shared/ReactFeatureFlags';
 import {
   REACT_CONTEXT_TYPE,
@@ -602,11 +601,7 @@ export function bailoutHooks(
   workInProgress.updateQueue = current.updateQueue;
   // TODO: Don't need to reset the flags here, because they're reset in the
   // complete phase (bubbleProperties).
-  if (
-    __DEV__ &&
-    enableStrictEffects &&
-    (workInProgress.mode & StrictEffectsMode) !== NoMode
-  ) {
+  if (__DEV__ && (workInProgress.mode & StrictEffectsMode) !== NoMode) {
     workInProgress.flags &= ~(
       MountPassiveDevEffect |
       MountLayoutDevEffect |
@@ -1888,7 +1883,6 @@ function mountEffect(
 ): void {
   if (
     __DEV__ &&
-    enableStrictEffects &&
     (currentlyRenderingFiber.mode & StrictEffectsMode) !== NoMode
   ) {
     return mountEffectImpl(
@@ -1984,7 +1978,6 @@ function mountLayoutEffect(
   let fiberFlags: Flags = UpdateEffect | LayoutStaticEffect;
   if (
     __DEV__ &&
-    enableStrictEffects &&
     (currentlyRenderingFiber.mode & StrictEffectsMode) !== NoMode
   ) {
     fiberFlags |= MountLayoutDevEffect;
@@ -2051,7 +2044,6 @@ function mountImperativeHandle<T>(
   let fiberFlags: Flags = UpdateEffect | LayoutStaticEffect;
   if (
     __DEV__ &&
-    enableStrictEffects &&
     (currentlyRenderingFiber.mode & StrictEffectsMode) !== NoMode
   ) {
     fiberFlags |= MountLayoutDevEffect;
diff --git a/packages/react-reconciler/src/ReactFiberHooks.old.js b/packages/react-reconciler/src/ReactFiberHooks.old.js
index 283e9daedd046..97aa7dcd4a41a 100644
--- a/packages/react-reconciler/src/ReactFiberHooks.old.js
+++ b/packages/react-reconciler/src/ReactFiberHooks.old.js
@@ -41,7 +41,6 @@ import {
   enableUseHook,
   enableUseMemoCacheHook,
   enableUseEventHook,
-  enableStrictEffects,
 } from 'shared/ReactFeatureFlags';
 import {
   REACT_CONTEXT_TYPE,
@@ -602,11 +601,7 @@ export function bailoutHooks(
   workInProgress.updateQueue = current.updateQueue;
   // TODO: Don't need to reset the flags here, because they're reset in the
   // complete phase (bubbleProperties).
-  if (
-    __DEV__ &&
-    enableStrictEffects &&
-    (workInProgress.mode & StrictEffectsMode) !== NoMode
-  ) {
+  if (__DEV__ && (workInProgress.mode & StrictEffectsMode) !== NoMode) {
     workInProgress.flags &= ~(
       MountPassiveDevEffect |
       MountLayoutDevEffect |
@@ -1888,7 +1883,6 @@ function mountEffect(
 ): void {
   if (
     __DEV__ &&
-    enableStrictEffects &&
     (currentlyRenderingFiber.mode & StrictEffectsMode) !== NoMode
   ) {
     return mountEffectImpl(
@@ -1984,7 +1978,6 @@ function mountLayoutEffect(
   let fiberFlags: Flags = UpdateEffect | LayoutStaticEffect;
   if (
     __DEV__ &&
-    enableStrictEffects &&
     (currentlyRenderingFiber.mode & StrictEffectsMode) !== NoMode
   ) {
     fiberFlags |= MountLayoutDevEffect;
@@ -2051,7 +2044,6 @@ function mountImperativeHandle<T>(
   let fiberFlags: Flags = UpdateEffect | LayoutStaticEffect;
   if (
     __DEV__ &&
-    enableStrictEffects &&
     (currentlyRenderingFiber.mode & StrictEffectsMode) !== NoMode
   ) {
     fiberFlags |= MountLayoutDevEffect;
diff --git a/packages/react-reconciler/src/ReactFiberWorkLoop.new.js b/packages/react-reconciler/src/ReactFiberWorkLoop.new.js
index c980402c30b43..cc2f1af4af59d 100644
--- a/packages/react-reconciler/src/ReactFiberWorkLoop.new.js
+++ b/packages/react-reconciler/src/ReactFiberWorkLoop.new.js
@@ -35,7 +35,6 @@ import {
   enableDebugTracing,
   enableSchedulingProfiler,
   disableSchedulerTimeoutInWorkLoop,
-  enableStrictEffects,
   skipUnmountedBoundaries,
   enableUpdaterTracking,
   enableCache,
@@ -2610,7 +2609,7 @@ function commitRootImpl(
     legacyErrorBoundariesThatAlreadyFailed = null;
   }
 
-  if (__DEV__ && enableStrictEffects) {
+  if (__DEV__) {
     if (!rootDidHavePassiveEffects) {
       commitDoubleInvokeEffectsInDEV(root, false);
     }
@@ -2887,7 +2886,7 @@ function flushPassiveEffectsImpl() {
     markPassiveEffectsStopped();
   }
 
-  if (__DEV__ && enableStrictEffects) {
+  if (__DEV__) {
     commitDoubleInvokeEffectsInDEV(root, true);
   }
 
@@ -3356,7 +3355,7 @@ function commitDoubleInvokeEffectsInDEV(
   root: FiberRoot,
   hasPassiveEffects: boolean,
 ) {
-  if (__DEV__ && enableStrictEffects) {
+  if (__DEV__) {
     if (useModernStrictMode) {
       let doubleInvokeEffects = true;
 
diff --git a/packages/react-reconciler/src/ReactFiberWorkLoop.old.js b/packages/react-reconciler/src/ReactFiberWorkLoop.old.js
index 72b520b8e18a1..8c15823869d77 100644
--- a/packages/react-reconciler/src/ReactFiberWorkLoop.old.js
+++ b/packages/react-reconciler/src/ReactFiberWorkLoop.old.js
@@ -35,7 +35,6 @@ import {
   enableDebugTracing,
   enableSchedulingProfiler,
   disableSchedulerTimeoutInWorkLoop,
-  enableStrictEffects,
   skipUnmountedBoundaries,
   enableUpdaterTracking,
   enableCache,
@@ -2610,7 +2609,7 @@ function commitRootImpl(
     legacyErrorBoundariesThatAlreadyFailed = null;
   }
 
-  if (__DEV__ && enableStrictEffects) {
+  if (__DEV__) {
     if (!rootDidHavePassiveEffects) {
       commitDoubleInvokeEffectsInDEV(root, false);
     }
@@ -2887,7 +2886,7 @@ function flushPassiveEffectsImpl() {
     markPassiveEffectsStopped();
   }
 
-  if (__DEV__ && enableStrictEffects) {
+  if (__DEV__) {
     commitDoubleInvokeEffectsInDEV(root, true);
   }
 
@@ -3356,7 +3355,7 @@ function commitDoubleInvokeEffectsInDEV(
   root: FiberRoot,
   hasPassiveEffects: boolean,
 ) {
-  if (__DEV__ && enableStrictEffects) {
+  if (__DEV__) {
     if (useModernStrictMode) {
       let doubleInvokeEffects = true;
 
diff --git a/packages/react-reconciler/src/__tests__/ReactOffscreenStrictMode-test.js b/packages/react-reconciler/src/__tests__/ReactOffscreenStrictMode-test.js
index 0771e596d9111..a3f45d8aa1ac6 100644
--- a/packages/react-reconciler/src/__tests__/ReactOffscreenStrictMode-test.js
+++ b/packages/react-reconciler/src/__tests__/ReactOffscreenStrictMode-test.js
@@ -31,7 +31,7 @@ describe('ReactOffscreenStrictMode', () => {
     return <span>label</span>;
   }
 
-  // @gate __DEV__ && enableStrictEffects && enableOffscreen
+  // @gate __DEV__ && enableOffscreen
   it('should trigger strict effects when offscreen is visible', () => {
     act(() => {
       ReactNoop.render(
@@ -55,7 +55,7 @@ describe('ReactOffscreenStrictMode', () => {
     ]);
   });
 
-  // @gate __DEV__ && enableStrictEffects && enableOffscreen && useModernStrictMode
+  // @gate __DEV__ && enableOffscreen && useModernStrictMode
   it('should not trigger strict effects when offscreen is hidden', () => {
     act(() => {
       ReactNoop.render(
@@ -154,7 +154,7 @@ describe('ReactOffscreenStrictMode', () => {
     });
   });
 
-  // @gate __DEV__ && enableStrictEffects && enableOffscreen
+  // @gate __DEV__ && enableOffscreen
   it('should double invoke effects on unsuspended child', async () => {
     let shouldSuspend = true;
     let resolve;
diff --git a/packages/react-reconciler/src/__tests__/StrictEffectsMode-test.js b/packages/react-reconciler/src/__tests__/StrictEffectsMode-test.js
index 072addc637a72..aceb7d05d2d1e 100644
--- a/packages/react-reconciler/src/__tests__/StrictEffectsMode-test.js
+++ b/packages/react-reconciler/src/__tests__/StrictEffectsMode-test.js
@@ -27,7 +27,6 @@ describe('StrictEffectsMode', () => {
     return gate(
       flags =>
         flags.build === 'development' &&
-        flags.enableStrictEffects &&
         flags.createRootStrictEffectsByDefault &&
         flags.dfsEffectsRefactor,
     );
diff --git a/packages/react-reconciler/src/__tests__/StrictEffectsModeDefaults-test.internal.js b/packages/react-reconciler/src/__tests__/StrictEffectsModeDefaults-test.internal.js
index 6fda4fe1314cb..7a7603d3d9283 100644
--- a/packages/react-reconciler/src/__tests__/StrictEffectsModeDefaults-test.internal.js
+++ b/packages/react-reconciler/src/__tests__/StrictEffectsModeDefaults-test.internal.js
@@ -24,7 +24,6 @@ describe('StrictEffectsMode defaults', () => {
     act = require('jest-react').act;
 
     const ReactFeatureFlags = require('shared/ReactFeatureFlags');
-    ReactFeatureFlags.enableStrictEffects = __DEV__;
     ReactFeatureFlags.createRootStrictEffectsByDefault = __DEV__;
   });
 
diff --git a/packages/react/src/__tests__/ReactStrictMode-test.internal.js b/packages/react/src/__tests__/ReactStrictMode-test.internal.js
index 35627e2793701..9661d0f72e35d 100644
--- a/packages/react/src/__tests__/ReactStrictMode-test.internal.js
+++ b/packages/react/src/__tests__/ReactStrictMode-test.internal.js
@@ -20,9 +20,6 @@ describe('ReactStrictMode', () => {
     ReactDOMClient = require('react-dom/client');
 
     act = require('jest-react').act;
-
-    const ReactFeatureFlags = require('shared/ReactFeatureFlags');
-    ReactFeatureFlags.enableStrictEffects = __DEV__;
   });
 
   describe('levels', () => {
diff --git a/packages/shared/ReactFeatureFlags.js b/packages/shared/ReactFeatureFlags.js
index 59122193ab10d..9caa256a1449c 100644
--- a/packages/shared/ReactFeatureFlags.js
+++ b/packages/shared/ReactFeatureFlags.js
@@ -229,10 +229,6 @@ export const enableSchedulingProfiler = __PROFILE__;
 // reducers by double invoking them in StrictLegacyMode.
 export const debugRenderPhaseSideEffectsForStrictMode = __DEV__;
 
-// Helps identify code that is not safe for planned Offscreen API and Suspense semantics;
-// this feature flag only impacts StrictEffectsMode.
-export const enableStrictEffects = __DEV__;
-
 // To preserve the "Pause on caught exceptions" behavior of the debugger, we
 // replay the begin phase of a failed component inside invokeGuardedCallback.
 export const replayFailedUnitOfWorkWithInvokeGuardedCallback = __DEV__;
diff --git a/packages/shared/forks/ReactFeatureFlags.native-fb.js b/packages/shared/forks/ReactFeatureFlags.native-fb.js
index 2c31bb577c707..c122058bc7455 100644
--- a/packages/shared/forks/ReactFeatureFlags.native-fb.js
+++ b/packages/shared/forks/ReactFeatureFlags.native-fb.js
@@ -65,7 +65,6 @@ export const enableGetInspectorDataForInstanceInProduction = true;
 export const enableNewReconciler = false;
 export const deferRenderPhaseUpdateToNextBatch = false;
 
-export const enableStrictEffects = __DEV__;
 export const createRootStrictEffectsByDefault = false;
 
 export const disableSchedulerTimeoutInWorkLoop = false;
diff --git a/packages/shared/forks/ReactFeatureFlags.native-oss.js b/packages/shared/forks/ReactFeatureFlags.native-oss.js
index 56fb6dd20b9fe..84b51658e920a 100644
--- a/packages/shared/forks/ReactFeatureFlags.native-oss.js
+++ b/packages/shared/forks/ReactFeatureFlags.native-oss.js
@@ -55,7 +55,6 @@ export const enableGetInspectorDataForInstanceInProduction = false;
 export const enableNewReconciler = false;
 export const deferRenderPhaseUpdateToNextBatch = false;
 
-export const enableStrictEffects = false;
 export const createRootStrictEffectsByDefault = false;
 export const enableUseRefAccessWarning = false;
 
diff --git a/packages/shared/forks/ReactFeatureFlags.test-renderer.js b/packages/shared/forks/ReactFeatureFlags.test-renderer.js
index b909a05fd79b2..ae53daa68d190 100644
--- a/packages/shared/forks/ReactFeatureFlags.test-renderer.js
+++ b/packages/shared/forks/ReactFeatureFlags.test-renderer.js
@@ -55,7 +55,6 @@ export const enableGetInspectorDataForInstanceInProduction = false;
 export const enableNewReconciler = false;
 export const deferRenderPhaseUpdateToNextBatch = false;
 
-export const enableStrictEffects = false;
 export const createRootStrictEffectsByDefault = false;
 export const enableUseRefAccessWarning = false;
 
diff --git a/packages/shared/forks/ReactFeatureFlags.test-renderer.native.js b/packages/shared/forks/ReactFeatureFlags.test-renderer.native.js
index 309a9a5acdf8e..656bf8961d61e 100644
--- a/packages/shared/forks/ReactFeatureFlags.test-renderer.native.js
+++ b/packages/shared/forks/ReactFeatureFlags.test-renderer.native.js
@@ -54,7 +54,6 @@ export const enableUseMemoCacheHook = false;
 export const enableUseEventHook = false;
 export const enableCapturePhaseSelectiveHydrationWithoutDiscreteEventReplay = true;
 export const enableClientRenderFallbackOnTextMismatch = true;
-export const enableStrictEffects = false;
 export const createRootStrictEffectsByDefault = false;
 export const enableUseRefAccessWarning = false;
 
diff --git a/packages/shared/forks/ReactFeatureFlags.test-renderer.www.js b/packages/shared/forks/ReactFeatureFlags.test-renderer.www.js
index 21c525917462a..0b35db3a8ea55 100644
--- a/packages/shared/forks/ReactFeatureFlags.test-renderer.www.js
+++ b/packages/shared/forks/ReactFeatureFlags.test-renderer.www.js
@@ -55,7 +55,6 @@ export const enableGetInspectorDataForInstanceInProduction = false;
 export const enableNewReconciler = false;
 export const deferRenderPhaseUpdateToNextBatch = false;
 
-export const enableStrictEffects = true;
 export const createRootStrictEffectsByDefault = false;
 export const enableUseRefAccessWarning = false;
 
diff --git a/packages/shared/forks/ReactFeatureFlags.testing.js b/packages/shared/forks/ReactFeatureFlags.testing.js
index 0252698dbad45..e471b432f8fe3 100644
--- a/packages/shared/forks/ReactFeatureFlags.testing.js
+++ b/packages/shared/forks/ReactFeatureFlags.testing.js
@@ -55,7 +55,6 @@ export const enableGetInspectorDataForInstanceInProduction = false;
 export const enableNewReconciler = false;
 export const deferRenderPhaseUpdateToNextBatch = false;
 
-export const enableStrictEffects = false;
 export const createRootStrictEffectsByDefault = false;
 export const enableUseRefAccessWarning = false;
 
diff --git a/packages/shared/forks/ReactFeatureFlags.testing.www.js b/packages/shared/forks/ReactFeatureFlags.testing.www.js
index 4fdd8577871d1..f41249dad84cc 100644
--- a/packages/shared/forks/ReactFeatureFlags.testing.www.js
+++ b/packages/shared/forks/ReactFeatureFlags.testing.www.js
@@ -55,7 +55,6 @@ export const enableGetInspectorDataForInstanceInProduction = false;
 export const enableNewReconciler = false;
 export const deferRenderPhaseUpdateToNextBatch = false;
 
-export const enableStrictEffects = false;
 export const createRootStrictEffectsByDefault = false;
 export const enableUseRefAccessWarning = false;
 
diff --git a/packages/shared/forks/ReactFeatureFlags.www-dynamic.js b/packages/shared/forks/ReactFeatureFlags.www-dynamic.js
index c08abf443fec1..882871de6f507 100644
--- a/packages/shared/forks/ReactFeatureFlags.www-dynamic.js
+++ b/packages/shared/forks/ReactFeatureFlags.www-dynamic.js
@@ -57,7 +57,6 @@ export const enableTrustedTypesIntegration = false;
 export const disableSchedulerTimeoutBasedOnReactExpirationTime = false;
 export const disableNativeComponentFrames = false;
 export const createRootStrictEffectsByDefault = false;
-export const enableStrictEffects = false;
 export const allowConcurrentByDefault = true;
 // You probably *don't* want to add more hardcoded ones.
 // Instead, try to add them above with the __VARIANT__ value.
diff --git a/packages/shared/forks/ReactFeatureFlags.www.js b/packages/shared/forks/ReactFeatureFlags.www.js
index 33f94ae63da40..92739ff777b3c 100644
--- a/packages/shared/forks/ReactFeatureFlags.www.js
+++ b/packages/shared/forks/ReactFeatureFlags.www.js
@@ -39,8 +39,6 @@ export const {
 // On WWW, __EXPERIMENTAL__ is used for a new modern build.
 // It's not used anywhere in production yet.
 
-export const enableStrictEffects: boolean =
-  __DEV__ && dynamicFeatureFlags.enableStrictEffects;
 export const debugRenderPhaseSideEffectsForStrictMode = __DEV__;
 export const enableProfilerTimer = __PROFILE__;
 export const enableProfilerCommitHooks = __PROFILE__;