diff --git a/packages/react-dom/src/client/ReactDOMHostConfig.js b/packages/react-dom/src/client/ReactDOMHostConfig.js
index 2e9224817acb9..e0ee9f4e1da1d 100644
--- a/packages/react-dom/src/client/ReactDOMHostConfig.js
+++ b/packages/react-dom/src/client/ReactDOMHostConfig.js
@@ -55,6 +55,7 @@ import {
   addRootEventTypesForResponderInstance,
   mountEventResponder,
   unmountEventResponder,
+  dispatchEventForResponderEventSystem,
 } from '../events/DOMEventResponderSystem';
 import {retryIfBlockedOn} from '../events/ReactDOMEventReplaying';
 
@@ -108,6 +109,10 @@ import {
   enableFlareAPI,
   enableFundamentalAPI,
 } from 'shared/ReactFeatureFlags';
+import {
+  RESPONDER_EVENT_SYSTEM,
+  IS_PASSIVE,
+} from 'legacy-events/EventSystemFlags';
 
 let SUPPRESS_HYDRATION_WARNING;
 if (__DEV__) {
@@ -447,10 +452,36 @@ export function insertInContainerBefore(
   }
 }
 
+function handleSimulateChildBlur(
+  child: Instance | TextInstance | SuspenseInstance,
+): void {
+  if (
+    enableFlareAPI &&
+    selectionInformation &&
+    child === selectionInformation.focusedElem
+  ) {
+    const targetFiber = getClosestInstanceFromNode(child);
+    // Simlulate a blur event to the React Flare responder system.
+    dispatchEventForResponderEventSystem(
+      'blur',
+      targetFiber,
+      ({
+        relatedTarget: null,
+        target: child,
+        timeStamp: Date.now(),
+        type: 'blur',
+      }: any),
+      ((child: any): Document | Element),
+      RESPONDER_EVENT_SYSTEM | IS_PASSIVE,
+    );
+  }
+}
+
 export function removeChild(
   parentInstance: Instance,
   child: Instance | TextInstance | SuspenseInstance,
 ): void {
+  handleSimulateChildBlur(child);
   parentInstance.removeChild(child);
 }
 
@@ -461,6 +492,7 @@ export function removeChildFromContainer(
   if (container.nodeType === COMMENT_NODE) {
     (container.parentNode: any).removeChild(child);
   } else {
+    handleSimulateChildBlur(child);
     container.removeChild(child);
   }
 }
diff --git a/packages/react-interactions/events/src/dom/__tests__/FocusWithin-test.internal.js b/packages/react-interactions/events/src/dom/__tests__/FocusWithin-test.internal.js
index d9808ce691a6e..12a2d7f03aec4 100644
--- a/packages/react-interactions/events/src/dom/__tests__/FocusWithin-test.internal.js
+++ b/packages/react-interactions/events/src/dom/__tests__/FocusWithin-test.internal.js
@@ -77,23 +77,24 @@ describe.each(table)('FocusWithin responder', hasPointerEvents => {
   describe('onFocusWithinChange', () => {
     let onFocusWithinChange, ref, innerRef, innerRef2;
 
+    const Component = ({show}) => {
+      const listener = useFocusWithin({
+        onFocusWithinChange,
+      });
+      return (
+        <div ref={ref} listeners={listener}>
+          {show && <input ref={innerRef} />}
+          <div ref={innerRef2} />
+        </div>
+      );
+    };
+
     beforeEach(() => {
       onFocusWithinChange = jest.fn();
       ref = React.createRef();
       innerRef = React.createRef();
       innerRef2 = React.createRef();
-      const Component = () => {
-        const listener = useFocusWithin({
-          onFocusWithinChange,
-        });
-        return (
-          <div ref={ref} listeners={listener}>
-            <div ref={innerRef} />
-            <div ref={innerRef2} />
-          </div>
-        );
-      };
-      ReactDOM.render(<Component />, container);
+      ReactDOM.render(<Component show={true} />, container);
     });
 
     it('is called after "blur" and "focus" events on focus target', () => {
@@ -140,28 +141,39 @@ describe.each(table)('FocusWithin responder', hasPointerEvents => {
       expect(onFocusWithinChange).toHaveBeenCalledTimes(2);
       expect(onFocusWithinChange).toHaveBeenCalledWith(false);
     });
+
+    it('is called after a focused element is unmounted', () => {
+      const target = createEventTarget(innerRef.current);
+      target.focus();
+      expect(onFocusWithinChange).toHaveBeenCalledTimes(1);
+      expect(onFocusWithinChange).toHaveBeenCalledWith(true);
+      ReactDOM.render(<Component show={false} />, container);
+      expect(onFocusWithinChange).toHaveBeenCalledTimes(2);
+      expect(onFocusWithinChange).toHaveBeenCalledWith(false);
+    });
   });
 
   describe('onFocusWithinVisibleChange', () => {
     let onFocusWithinVisibleChange, ref, innerRef, innerRef2;
 
+    const Component = ({show}) => {
+      const listener = useFocusWithin({
+        onFocusWithinVisibleChange,
+      });
+      return (
+        <div ref={ref} listeners={listener}>
+          {show && <input ref={innerRef} />}
+          <div ref={innerRef2} />
+        </div>
+      );
+    };
+
     beforeEach(() => {
       onFocusWithinVisibleChange = jest.fn();
       ref = React.createRef();
       innerRef = React.createRef();
       innerRef2 = React.createRef();
-      const Component = () => {
-        const listener = useFocusWithin({
-          onFocusWithinVisibleChange,
-        });
-        return (
-          <div ref={ref} listeners={listener}>
-            <div ref={innerRef} />
-            <div ref={innerRef2} />
-          </div>
-        );
-      };
-      ReactDOM.render(<Component />, container);
+      ReactDOM.render(<Component show={true} />, container);
     });
 
     it('is called after "focus" and "blur" on focus target if keyboard was used', () => {
@@ -258,6 +270,18 @@ describe.each(table)('FocusWithin responder', hasPointerEvents => {
       expect(onFocusWithinVisibleChange).toHaveBeenCalledTimes(2);
       expect(onFocusWithinVisibleChange).toHaveBeenCalledWith(false);
     });
+
+    it('is called after a focused element is unmounted', () => {
+      const inner = innerRef.current;
+      const target = createEventTarget(inner);
+      target.keydown({key: 'Tab'});
+      target.focus();
+      expect(onFocusWithinVisibleChange).toHaveBeenCalledTimes(1);
+      expect(onFocusWithinVisibleChange).toHaveBeenCalledWith(true);
+      ReactDOM.render(<Component show={false} />, container);
+      expect(onFocusWithinVisibleChange).toHaveBeenCalledTimes(2);
+      expect(onFocusWithinVisibleChange).toHaveBeenCalledWith(false);
+    });
   });
 
   it('expect displayName to show up for event component', () => {
diff --git a/packages/react-interactions/events/src/dom/testing-library/index.js b/packages/react-interactions/events/src/dom/testing-library/index.js
index d46f96a5058ce..f740a31040aa6 100644
--- a/packages/react-interactions/events/src/dom/testing-library/index.js
+++ b/packages/react-interactions/events/src/dom/testing-library/index.js
@@ -34,6 +34,7 @@ const createEventTarget = node => ({
   },
   focus(payload) {
     node.dispatchEvent(domEvents.focus(payload));
+    node.focus();
   },
   scroll(payload) {
     node.dispatchEvent(domEvents.scroll(payload));