diff --git a/packages/react-devtools-shared/src/backend/fiber/renderer.js b/packages/react-devtools-shared/src/backend/fiber/renderer.js
index ef8bac0099a2b..3ad1b7ba4598d 100644
--- a/packages/react-devtools-shared/src/backend/fiber/renderer.js
+++ b/packages/react-devtools-shared/src/backend/fiber/renderer.js
@@ -146,6 +146,7 @@ import type {
 import type {Source} from 'react-devtools-shared/src/shared/types';
 import {getSourceLocationByFiber} from './DevToolsFiberComponentStack';
 import {formatOwnerStack} from '../shared/DevToolsOwnerStack';
+import {ActivityComponent} from 'react-reconciler/src/ReactWorkTags';
 
 // Kinds
 const FIBER_INSTANCE = 0;
@@ -385,6 +386,7 @@ export function getInternalReactConstants(version: string): {
       YieldComponent: -1, // Removed
       Throw: 29,
       ViewTransitionComponent: 30, // Experimental
+      ActivityComponent: 31,
     };
   } else if (gte(version, '17.0.0-alpha')) {
     ReactTypeOfWork = {
@@ -421,6 +423,7 @@ export function getInternalReactConstants(version: string): {
       YieldComponent: -1, // Removed
       Throw: -1, // Doesn't exist yet
       ViewTransitionComponent: -1, // Doesn't exist yet
+      ActivityComponent: -1, // Doesn't exist yet
     };
   } else if (gte(version, '16.6.0-beta.0')) {
     ReactTypeOfWork = {
@@ -457,6 +460,7 @@ export function getInternalReactConstants(version: string): {
       YieldComponent: -1, // Removed
       Throw: -1, // Doesn't exist yet
       ViewTransitionComponent: -1, // Doesn't exist yet
+      ActivityComponent: -1, // Doesn't exist yet
     };
   } else if (gte(version, '16.4.3-alpha')) {
     ReactTypeOfWork = {
@@ -493,6 +497,7 @@ export function getInternalReactConstants(version: string): {
       YieldComponent: -1, // Removed
       Throw: -1, // Doesn't exist yet
       ViewTransitionComponent: -1, // Doesn't exist yet
+      ActivityComponent: -1, // Doesn't exist yet
     };
   } else {
     ReactTypeOfWork = {
@@ -529,6 +534,7 @@ export function getInternalReactConstants(version: string): {
       YieldComponent: 9,
       Throw: -1, // Doesn't exist yet
       ViewTransitionComponent: -1, // Doesn't exist yet
+      ActivityComponent: -1, // Doesn't exist yet
     };
   }
   // **********************************************************
@@ -622,6 +628,8 @@ export function getInternalReactConstants(version: string): {
     }
 
     switch (tag) {
+      case ActivityComponent:
+        return 'Activity';
       case CacheComponent:
         return 'Cache';
       case ClassComponent:
@@ -1480,6 +1488,7 @@ export function attach(
         return true;
       case HostPortal:
       case HostText:
+      case ActivityComponent:
       case LegacyHiddenComponent:
       case OffscreenComponent:
       case Throw:
diff --git a/packages/react-devtools-shared/src/backend/types.js b/packages/react-devtools-shared/src/backend/types.js
index 7b0d801026acc..56fb9a8ec315b 100644
--- a/packages/react-devtools-shared/src/backend/types.js
+++ b/packages/react-devtools-shared/src/backend/types.js
@@ -77,6 +77,7 @@ export type WorkTagMap = {
   YieldComponent: WorkTag,
   Throw: WorkTag,
   ViewTransitionComponent: WorkTag,
+  ActivityComponent: WorkTag,
 };
 
 export type HostInstance = Object;
diff --git a/packages/react-reconciler/src/ReactFiber.js b/packages/react-reconciler/src/ReactFiber.js
index 1ebe08b76963e..c96380939cfa0 100644
--- a/packages/react-reconciler/src/ReactFiber.js
+++ b/packages/react-reconciler/src/ReactFiber.js
@@ -72,6 +72,7 @@ import {
   TracingMarkerComponent,
   Throw,
   ViewTransitionComponent,
+  ActivityComponent,
 } from './ReactWorkTags';
 import {OffscreenVisible} from './ReactFiberActivityComponent';
 import {getComponentNameFromOwner} from 'react-reconciler/src/getComponentNameFromFiber';
@@ -108,6 +109,7 @@ import {
   REACT_TRACING_MARKER_TYPE,
   REACT_ELEMENT_TYPE,
   REACT_VIEW_TRANSITION_TYPE,
+  REACT_ACTIVITY_TYPE,
 } from 'shared/ReactSymbols';
 import {TransitionTracingMarker} from './ReactFiberTracingMarkerComponent';
 import {
@@ -595,6 +597,8 @@ export function createFiberFromTypeAndProps(
     }
   } else {
     getTag: switch (type) {
+      case REACT_ACTIVITY_TYPE:
+        return createFiberFromActivity(pendingProps, mode, lanes, key);
       case REACT_FRAGMENT_TYPE:
         return createFiberFromFragment(pendingProps.children, mode, lanes, key);
       case REACT_STRICT_MODE_TYPE:
@@ -874,6 +878,17 @@ export function createFiberFromOffscreen(
   fiber.stateNode = primaryChildInstance;
   return fiber;
 }
+export function createFiberFromActivity(
+  pendingProps: OffscreenProps,
+  mode: TypeOfMode,
+  lanes: Lanes,
+  key: null | string,
+): Fiber {
+  const fiber = createFiber(ActivityComponent, pendingProps, key, mode);
+  fiber.elementType = REACT_ACTIVITY_TYPE;
+  fiber.lanes = lanes;
+  return fiber;
+}
 
 export function createFiberFromViewTransition(
   pendingProps: ViewTransitionProps,
diff --git a/packages/react-reconciler/src/ReactFiberBeginWork.js b/packages/react-reconciler/src/ReactFiberBeginWork.js
index 6f4acf97cf455..bea69b2063de2 100644
--- a/packages/react-reconciler/src/ReactFiberBeginWork.js
+++ b/packages/react-reconciler/src/ReactFiberBeginWork.js
@@ -77,6 +77,7 @@ import {
   TracingMarkerComponent,
   Throw,
   ViewTransitionComponent,
+  ActivityComponent,
 } from './ReactWorkTags';
 import {
   NoFlags,
@@ -867,6 +868,46 @@ function deferHiddenOffscreenComponent(
 // fork the function.
 const updateLegacyHiddenComponent = updateOffscreenComponent;
 
+function updateActivityComponent(
+  current: null | Fiber,
+  workInProgress: Fiber,
+  renderLanes: Lanes,
+) {
+  const nextProps = workInProgress.pendingProps;
+  const nextChildren = nextProps.children;
+  const nextMode = nextProps.mode;
+  const mode = workInProgress.mode;
+  const offscreenChildProps: OffscreenProps = {
+    mode: nextMode,
+    children: nextChildren,
+  };
+
+  if (current === null) {
+    const primaryChildFragment = mountWorkInProgressOffscreenFiber(
+      offscreenChildProps,
+      mode,
+      renderLanes,
+    );
+    primaryChildFragment.ref = workInProgress.ref;
+    workInProgress.child = primaryChildFragment;
+    primaryChildFragment.return = workInProgress;
+
+    return primaryChildFragment;
+  } else {
+    const currentChild: Fiber = (current.child: any);
+
+    const primaryChildFragment = updateWorkInProgressOffscreenFiber(
+      currentChild,
+      offscreenChildProps,
+    );
+
+    primaryChildFragment.ref = workInProgress.ref;
+    workInProgress.child = primaryChildFragment;
+    primaryChildFragment.return = workInProgress;
+    return primaryChildFragment;
+  }
+}
+
 function updateCacheComponent(
   current: Fiber | null,
   workInProgress: Fiber,
@@ -4024,6 +4065,9 @@ function beginWork(
       }
       break;
     }
+    case ActivityComponent: {
+      return updateActivityComponent(current, workInProgress, renderLanes);
+    }
     case OffscreenComponent: {
       return updateOffscreenComponent(current, workInProgress, renderLanes);
     }
diff --git a/packages/react-reconciler/src/ReactFiberCompleteWork.js b/packages/react-reconciler/src/ReactFiberCompleteWork.js
index 89012e78cf652..dc8e9a1bffa01 100644
--- a/packages/react-reconciler/src/ReactFiberCompleteWork.js
+++ b/packages/react-reconciler/src/ReactFiberCompleteWork.js
@@ -76,6 +76,7 @@ import {
   TracingMarkerComponent,
   Throw,
   ViewTransitionComponent,
+  ActivityComponent,
 } from './ReactWorkTags';
 import {NoMode, ConcurrentMode, ProfileMode} from './ReactTypeOfMode';
 import {
@@ -959,6 +960,7 @@ function completeWork(
       }
       // Fallthrough
     }
+    case ActivityComponent:
     case LazyComponent:
     case SimpleMemoComponent:
     case FunctionComponent:
diff --git a/packages/react-reconciler/src/ReactWorkTags.js b/packages/react-reconciler/src/ReactWorkTags.js
index 5de62ebeb7569..4b01934be7781 100644
--- a/packages/react-reconciler/src/ReactWorkTags.js
+++ b/packages/react-reconciler/src/ReactWorkTags.js
@@ -38,7 +38,8 @@ export type WorkTag =
   | 27
   | 28
   | 29
-  | 30;
+  | 30
+  | 31;
 
 export const FunctionComponent = 0;
 export const ClassComponent = 1;
@@ -69,3 +70,4 @@ export const HostSingleton = 27;
 export const IncompleteFunctionComponent = 28;
 export const Throw = 29;
 export const ViewTransitionComponent = 30;
+export const ActivityComponent = 31;
diff --git a/packages/react-reconciler/src/getComponentNameFromFiber.js b/packages/react-reconciler/src/getComponentNameFromFiber.js
index 04ad072c2583f..670475cdec5a0 100644
--- a/packages/react-reconciler/src/getComponentNameFromFiber.js
+++ b/packages/react-reconciler/src/getComponentNameFromFiber.js
@@ -47,6 +47,7 @@ import {
   TracingMarkerComponent,
   Throw,
   ViewTransitionComponent,
+  ActivityComponent,
 } from 'react-reconciler/src/ReactWorkTags';
 import getComponentNameFromType from 'shared/getComponentNameFromType';
 import {REACT_STRICT_MODE_TYPE} from 'shared/ReactSymbols';
@@ -85,6 +86,8 @@ export function getComponentNameFromOwner(
 export default function getComponentNameFromFiber(fiber: Fiber): string | null {
   const {tag, type} = fiber;
   switch (tag) {
+    case ActivityComponent:
+      return 'Activity';
     case CacheComponent:
       return 'Cache';
     case ContextConsumer:
diff --git a/packages/react-server/src/ReactFizzServer.js b/packages/react-server/src/ReactFizzServer.js
index 041ef31e2bd3d..cc4173486404b 100644
--- a/packages/react-server/src/ReactFizzServer.js
+++ b/packages/react-server/src/ReactFizzServer.js
@@ -154,6 +154,7 @@ import {
   REACT_OFFSCREEN_TYPE,
   REACT_POSTPONE_TYPE,
   REACT_VIEW_TRANSITION_TYPE,
+  REACT_ACTIVITY_TYPE,
 } from 'shared/ReactSymbols';
 import ReactSharedInternals from 'shared/ReactSharedInternals';
 import {
@@ -2261,6 +2262,7 @@ function renderElement(
       task.keyPath = prevKeyPath;
       return;
     }
+    case REACT_ACTIVITY_TYPE:
     case REACT_OFFSCREEN_TYPE: {
       renderOffscreen(request, task, keyPath, props);
       return;
diff --git a/packages/react/src/ReactClient.js b/packages/react/src/ReactClient.js
index 33175a9a77f35..b48a3cdb1a74e 100644
--- a/packages/react/src/ReactClient.js
+++ b/packages/react/src/ReactClient.js
@@ -15,7 +15,7 @@ import {
   REACT_SUSPENSE_TYPE,
   REACT_SUSPENSE_LIST_TYPE,
   REACT_LEGACY_HIDDEN_TYPE,
-  REACT_OFFSCREEN_TYPE,
+  REACT_ACTIVITY_TYPE,
   REACT_SCOPE_TYPE,
   REACT_TRACING_MARKER_TYPE,
   REACT_VIEW_TRANSITION_TYPE,
@@ -116,7 +116,7 @@ export {
   useDeferredValue,
   REACT_SUSPENSE_LIST_TYPE as unstable_SuspenseList,
   REACT_LEGACY_HIDDEN_TYPE as unstable_LegacyHidden,
-  REACT_OFFSCREEN_TYPE as unstable_Activity,
+  REACT_ACTIVITY_TYPE as unstable_Activity,
   getCacheForType as unstable_getCacheForType,
   useCacheRefresh as unstable_useCacheRefresh,
   use,
diff --git a/packages/shared/ReactSymbols.js b/packages/shared/ReactSymbols.js
index fc5893585900f..1fd00cd76d8c1 100644
--- a/packages/shared/ReactSymbols.js
+++ b/packages/shared/ReactSymbols.js
@@ -34,6 +34,7 @@ export const REACT_MEMO_TYPE: symbol = Symbol.for('react.memo');
 export const REACT_LAZY_TYPE: symbol = Symbol.for('react.lazy');
 export const REACT_SCOPE_TYPE: symbol = Symbol.for('react.scope');
 export const REACT_OFFSCREEN_TYPE: symbol = Symbol.for('react.offscreen');
+export const REACT_ACTIVITY_TYPE: symbol = Symbol.for('react.activity');
 export const REACT_LEGACY_HIDDEN_TYPE: symbol = Symbol.for(
   'react.legacy_hidden',
 );
diff --git a/packages/shared/isValidElementType.js b/packages/shared/isValidElementType.js
index cea90aebb14f6..df977acd4ecd2 100644
--- a/packages/shared/isValidElementType.js
+++ b/packages/shared/isValidElementType.js
@@ -24,6 +24,7 @@ import {
   REACT_OFFSCREEN_TYPE,
   REACT_TRACING_MARKER_TYPE,
   REACT_VIEW_TRANSITION_TYPE,
+  REACT_ACTIVITY_TYPE,
 } from 'shared/ReactSymbols';
 import {
   enableScopeAPI,
@@ -50,6 +51,7 @@ export default function isValidElementType(type: mixed): boolean {
     type === REACT_SUSPENSE_TYPE ||
     type === REACT_SUSPENSE_LIST_TYPE ||
     (enableLegacyHidden && type === REACT_LEGACY_HIDDEN_TYPE) ||
+    type === REACT_ACTIVITY_TYPE ||
     type === REACT_OFFSCREEN_TYPE ||
     (enableScopeAPI && type === REACT_SCOPE_TYPE) ||
     (enableTransitionTracing && type === REACT_TRACING_MARKER_TYPE) ||