diff --git a/packages/react-dom/src/events/DOMEventResponderSystem.js b/packages/react-dom/src/events/DOMEventResponderSystem.js
index 14bd5f5fff734..2d22140d6f12c 100644
--- a/packages/react-dom/src/events/DOMEventResponderSystem.js
+++ b/packages/react-dom/src/events/DOMEventResponderSystem.js
@@ -12,7 +12,7 @@ import {
   PASSIVE_NOT_SUPPORTED,
 } from 'legacy-events/EventSystemFlags';
 import type {AnyNativeEvent} from 'legacy-events/PluginModuleType';
-import {HostComponent, ScopeComponent} from 'shared/ReactWorkTags';
+import {HostComponent, ScopeComponent, HostPortal} from 'shared/ReactWorkTags';
 import type {EventPriority} from 'shared/ReactTypes';
 import type {
   ReactDOMEventResponder,
@@ -451,9 +451,12 @@ function traverseAndHandleEventResponderInstances(
     isPassiveSupported,
   );
   let node = targetFiber;
+  let insidePortal = false;
   while (node !== null) {
     const {dependencies, tag} = node;
-    if (
+    if (tag === HostPortal) {
+      insidePortal = true;
+    } else if (
       (tag === HostComponent || tag === ScopeComponent) &&
       dependencies !== null
     ) {
@@ -465,7 +468,8 @@ function traverseAndHandleEventResponderInstances(
           const {props, responder, state} = responderInstance;
           if (
             !visitedResponders.has(responder) &&
-            validateResponderTargetEventTypes(eventType, responder)
+            validateResponderTargetEventTypes(eventType, responder) &&
+            (!insidePortal || responder.targetPortalPropagation)
           ) {
             visitedResponders.add(responder);
             const onEvent = responder.onEvent;
diff --git a/packages/react-dom/src/events/__tests__/DOMEventResponderSystem-test.internal.js b/packages/react-dom/src/events/__tests__/DOMEventResponderSystem-test.internal.js
index 83f17d0c1723d..c695a19fd3f61 100644
--- a/packages/react-dom/src/events/__tests__/DOMEventResponderSystem-test.internal.js
+++ b/packages/react-dom/src/events/__tests__/DOMEventResponderSystem-test.internal.js
@@ -28,6 +28,7 @@ function createEventResponder({
   onMount,
   onUnmount,
   getInitialState,
+  targetPortalPropagation,
 }) {
   return React.unstable_createResponder('TestEventResponder', {
     targetEventTypes,
@@ -37,6 +38,7 @@ function createEventResponder({
     onMount,
     onUnmount,
     getInitialState,
+    targetPortalPropagation,
   });
 }
 
@@ -1034,4 +1036,51 @@ describe('DOMEventResponderSystem', () => {
       },
     ]);
   });
+
+  it('should not propagate target events through portals by default', () => {
+    const buttonRef = React.createRef();
+    const onEvent = jest.fn();
+    const TestResponder = createEventResponder({
+      targetEventTypes: ['click'],
+      onEvent,
+    });
+    const domNode = document.createElement('div');
+    document.body.appendChild(domNode);
+    const Component = () => {
+      const listener = React.unstable_useResponder(TestResponder, {});
+      return (
+        <div listeners={listener}>
+          {ReactDOM.createPortal(<button ref={buttonRef} />, domNode)}
+        </div>
+      );
+    };
+    ReactDOM.render(<Component />, container);
+    dispatchClickEvent(buttonRef.current);
+    document.body.removeChild(domNode);
+    expect(onEvent).not.toBeCalled();
+  });
+
+  it('should propagate target events through portals when enabled', () => {
+    const buttonRef = React.createRef();
+    const onEvent = jest.fn();
+    const TestResponder = createEventResponder({
+      targetPortalPropagation: true,
+      targetEventTypes: ['click'],
+      onEvent,
+    });
+    const domNode = document.createElement('div');
+    document.body.appendChild(domNode);
+    const Component = () => {
+      const listener = React.unstable_useResponder(TestResponder, {});
+      return (
+        <div listeners={listener}>
+          {ReactDOM.createPortal(<button ref={buttonRef} />, domNode)}
+        </div>
+      );
+    };
+    ReactDOM.render(<Component />, container);
+    dispatchClickEvent(buttonRef.current);
+    document.body.removeChild(domNode);
+    expect(onEvent).toBeCalled();
+  });
 });
diff --git a/packages/react-interactions/events/src/dom/Focus.js b/packages/react-interactions/events/src/dom/Focus.js
index 8ae33233ad33e..434ac2370fa3b 100644
--- a/packages/react-interactions/events/src/dom/Focus.js
+++ b/packages/react-interactions/events/src/dom/Focus.js
@@ -293,6 +293,7 @@ function unmountFocusResponder(
 
 const focusResponderImpl = {
   targetEventTypes,
+  targetPortalPropagation: true,
   rootEventTypes,
   getInitialState(): FocusState {
     return {
@@ -430,6 +431,7 @@ function unmountFocusWithinResponder(
 
 const focusWithinResponderImpl = {
   targetEventTypes,
+  targetPortalPropagation: true,
   rootEventTypes,
   getInitialState(): FocusState {
     return {
diff --git a/packages/react-interactions/events/src/dom/Keyboard.js b/packages/react-interactions/events/src/dom/Keyboard.js
index 08cc19d1d3bfc..9f4cbc56e9e92 100644
--- a/packages/react-interactions/events/src/dom/Keyboard.js
+++ b/packages/react-interactions/events/src/dom/Keyboard.js
@@ -180,6 +180,7 @@ function dispatchKeyboardEvent(
 
 const keyboardResponderImpl = {
   targetEventTypes,
+  targetPortalPropagation: true,
   getInitialState(): KeyboardState {
     return {
       isActive: false,
diff --git a/packages/shared/ReactTypes.js b/packages/shared/ReactTypes.js
index 5e9a6b11df1d6..2e8a891bc2ead 100644
--- a/packages/shared/ReactTypes.js
+++ b/packages/shared/ReactTypes.js
@@ -96,6 +96,7 @@ export type ReactEventResponder<E, C> = {
   $$typeof: Symbol | number,
   displayName: string,
   targetEventTypes: null | Array<string>,
+  targetPortalPropagation: boolean,
   rootEventTypes: null | Array<string>,
   getInitialState: null | ((props: Object) => Object),
   onEvent:
diff --git a/packages/shared/createEventResponder.js b/packages/shared/createEventResponder.js
index 02373b9574668..c18b1595c4966 100644
--- a/packages/shared/createEventResponder.js
+++ b/packages/shared/createEventResponder.js
@@ -22,6 +22,7 @@ export default function createEventResponder<E, C>(
     onRootEvent,
     rootEventTypes,
     targetEventTypes,
+    targetPortalPropagation,
   } = responderConfig;
   const eventResponder = {
     $$typeof: REACT_RESPONDER_TYPE,
@@ -33,6 +34,7 @@ export default function createEventResponder<E, C>(
     onUnmount: onUnmount || null,
     rootEventTypes: rootEventTypes || null,
     targetEventTypes: targetEventTypes || null,
+    targetPortalPropagation: targetPortalPropagation || false,
   };
   // We use responder as a Map key later on. When we have a bad
   // polyfill, then we can't use it as a key as the polyfill tries