diff --git a/.changelog/5955-fix-react-19-support.md b/.changelog/5955-fix-react-19-support.md
new file mode 100644
index 0000000000..0a180f6e1d
--- /dev/null
+++ b/.changelog/5955-fix-react-19-support.md
@@ -0,0 +1,13 @@
+### Added
+
+- Added [#5552](https://github.com/microsoft/BotFramework-WebChat/issues/5552) and [#5850](https://github.com/microsoft/BotFramework-WebChat/issues/5850), support for React 19, in PR [#5955](https://github.com/microsoft/BotFramework-WebChat/pull/5955), by [@OEvgeny](https://github.com/OEvgeny)
+- 👷🏻 Pull request validation: added type definitions tests with `@types/react@19`, in PR [#5955](https://github.com/microsoft/BotFramework-WebChat/pull/5955), by [@OEvgeny](https://github.com/OEvgeny)
+
+### Removed
+
+- Components: removed the remaining `propTypes` and the `prop-types` dependency, React 19 ignores them, in PR [#5955](https://github.com/microsoft/BotFramework-WebChat/pull/5955), by [@OEvgeny](https://github.com/OEvgeny)
+
+### Fixed
+
+- Fixed Adaptive Cards submitting empty inputs in Strict Mode on React 19, in PR [#5955](https://github.com/microsoft/BotFramework-WebChat/pull/5955), by [@OEvgeny](https://github.com/OEvgeny)
+- Fixed `Composer` of the full bundle not calling a `children` function with `extraStyleSet`, in PR [#5955](https://github.com/microsoft/BotFramework-WebChat/pull/5955), by [@OEvgeny](https://github.com/OEvgeny)
diff --git a/.github/workflows/pull-request-validation.yml b/.github/workflows/pull-request-validation.yml
index 87ad9a7cd7..5ac684813c 100644
--- a/.github/workflows/pull-request-validation.yml
+++ b/.github/workflows/pull-request-validation.yml
@@ -281,6 +281,15 @@ jobs:
         run: ../../node_modules/.bin/tsd -t ./dist/botframework-webchat-core.d.mts
         working-directory: ./packages/core
 
+      # The steps above use @types/react@16 (our baseline), check with the types of the latest React too.
+      # In every workspace: packages that declare @types/react@16 would otherwise keep their own copy.
+      - name: Install @types/react@19 and @types/react-dom@19
+        run: npm install --no-save --workspaces --include-workspace-root @types/react@19 @types/react-dom@19
+
+      - name: Run tsd under packages/bundle with @types/react@19
+        run: ../../node_modules/.bin/tsd -t ./dist/botframework-webchat.d.mts
+        working-directory: ./packages/bundle
+
   bundler-test:
     name: Bundler test (${{ matrix.bundler }}, React ${{ matrix.react }})
     needs:
diff --git a/__tests__/html2/react19/asset/reactDOMWithoutRender.js b/__tests__/html2/react19/asset/reactDOMWithoutRender.js
deleted file mode 100644
index 03bedf7469..0000000000
--- a/__tests__/html2/react19/asset/reactDOMWithoutRender.js
+++ /dev/null
@@ -1,9 +0,0 @@
-// Emulates "react-dom" of React 19, where `ReactDOM.render()` was removed, on top of React 18.
-// Named exports are kept: react-film, bundled in the static build, imports `render` by name (spyip/react-film#110).
-import ReactDOM from '/__dist__/packages/bundle/static/react-dom.js';
-
-export * from '/__dist__/packages/bundle/static/react-dom.js';
-
-const { render: _render, ...ReactDOMWithoutRender } = ReactDOM;
-
-export default Object.freeze(ReactDOMWithoutRender);
diff --git a/__tests__/html2/react19/renderWebChat.esm.html b/__tests__/html2/react19/renderWebChat.esm.html
index 708d95f68c..dea7926f7a 100644
--- a/__tests__/html2/react19/renderWebChat.esm.html
+++ b/__tests__/html2/react19/renderWebChat.esm.html
@@ -1,23 +1,19 @@
 <!doctype html>
 <html lang="en-US">
   <head>
-    <title>renderWebChat() renders with the root passed when ReactDOM.render() is unavailable (ESM build)</title>
+    <title>React 19: renderWebChat() of the ESM build renders with the root passed</title>
     <link href="/assets/index.css" rel="stylesheet" type="text/css" />
   </head>
   <body>
     <main id="webchat"></main>
-    <!--
-      React 18 with "react-dom" emulating React 19 (no `ReactDOM.render()`).
-      TODO: Use React 19 once the static build no longer bundles react-film, which imports `render` from "react-dom" (removed, or https://github.com/spyip/react-film/pull/110 released and bumped): it fails to load with React 19 until then.
-    -->
     <script type="importmap">
       {
         "imports": {
           "@testduet/wait-for": "https://esm.sh/@testduet/wait-for",
           "botframework-webchat": "/__dist__/packages/bundle/static/botframework-webchat.js",
-          "react": "/__dist__/packages/bundle/static/react.js",
-          "react-dom": "./asset/reactDOMWithoutRender.js",
-          "react-dom/client": "/__dist__/packages/bundle/static/react-dom/client.js"
+          "react": "https://esm.sh/react@19.3.1?dev",
+          "react-dom": "https://esm.sh/react-dom@19.3.1?dev",
+          "react-dom/client": "https://esm.sh/react-dom@19.3.1/client?dev"
         }
       }
     </script>
@@ -37,8 +33,8 @@
         const { directLine, store } = testHelpers.createDirectLineEmulator();
         const webChatElement = document.getElementById('webchat');
 
-        // GIVEN: "react-dom" of React 18 without `ReactDOM.render()`, like React 19.
-        expect(ReactDOM.version).toEqual(expect.stringMatching(/^18\./u)); // React 18 underneath the emulation, see the import map.
+        // GIVEN: React 19, which no longer has `ReactDOM.render()`.
+        expect(ReactDOM.version).toBe('19.3.1');
         expect(ReactDOM.render).toBeUndefined();
 
         // WHEN: Web Chat is rendered by renderWebChat() into the element.
diff --git a/__tests__/html2/react19/strictMode.adaptiveCard.submit.html b/__tests__/html2/react19/strictMode.adaptiveCard.submit.html
new file mode 100644
index 0000000000..3b131769eb
--- /dev/null
+++ b/__tests__/html2/react19/strictMode.adaptiveCard.submit.html
@@ -0,0 +1,98 @@
+<!doctype html>
+<html lang="en-US">
+  <head>
+    <title>React 19: submits the typed value of an Adaptive Card in Strict Mode</title>
+    <link href="/assets/index.css" rel="stylesheet" type="text/css" />
+  </head>
+  <body>
+    <main id="webchat"></main>
+    <script type="importmap">
+      {
+        "imports": {
+          "@testduet/wait-for": "https://esm.sh/@testduet/wait-for",
+          "botframework-webchat": "/__dist__/packages/bundle/static/botframework-webchat.js",
+          "react": "https://esm.sh/react@19.3.1?dev",
+          "react-dom": "https://esm.sh/react-dom@19.3.1?dev",
+          "react-dom/client": "https://esm.sh/react-dom@19.3.1/client?dev"
+        }
+      }
+    </script>
+    <script type="module">
+      import '/test-harness.mjs';
+      import '/test-page-object.mjs';
+
+      import { waitFor } from '@testduet/wait-for';
+      import { createStoreWithOptions, ReactWebChat } from 'botframework-webchat';
+      import { createElement, StrictMode, version } from 'react';
+      import { createRoot } from 'react-dom/client';
+
+      run(async function () {
+        // TODO: This is for `createDirectLineEmulator` only, should find ways to eliminate this line.
+        window.WebChat = { createStoreWithOptions };
+
+        const { directLine, store } = testHelpers.createDirectLineEmulator();
+
+        // GIVEN: The development build of React 19, which calls `useMemo()` twice in Strict Mode and keeps the first result.
+        expect(version).toBe('19.3.1');
+
+        createRoot(document.getElementById('webchat')).render(
+          createElement(
+            StrictMode,
+            {},
+            createElement(ReactWebChat, { directLine, store, styleOptions: { hideSendBox: true } })
+          )
+        );
+
+        await pageConditions.uiConnected();
+
+        // GIVEN: A card with a text input and a "Submit" button without `data`, which sends the inputs as a post back.
+        await directLine.emulateIncomingActivity({
+          attachments: [
+            {
+              content: {
+                $schema: 'http://adaptivecards.io/schemas/adaptive-card.json',
+                actions: [{ title: 'Submit', type: 'Action.Submit' }],
+                body: [{ id: 'firstName', label: 'First name', type: 'Input.Text' }],
+                type: 'AdaptiveCard',
+                version: '1.3'
+              },
+              contentType: 'application/vnd.microsoft.card.adaptive'
+            }
+          ],
+          from: { role: 'bot' },
+          type: 'message'
+        });
+
+        await pageConditions.numActivitiesShown(1);
+
+        const input = document.querySelector('.ac-textInput input, input.ac-textInput');
+        const submitButton = document.querySelector('.ac-pushButton');
+
+        expect(submitButton).toHaveProperty('textContent', 'Submit');
+
+        // WHEN: "John" is typed into the input and the "Submit" button is clicked.
+        await host.click(input);
+        await host.sendKeys('John');
+
+        const { activity, resolveAll } = await directLine.actPostActivity(() => host.click(submitButton));
+
+        await resolveAll();
+
+        // THEN: The post back should have the typed value.
+        expect(activity).toHaveProperty('value', { firstName: 'John' });
+
+        // THEN: The input on screen should be the one the card read.
+        expect(document.querySelector('.ac-textInput input, input.ac-textInput')).toBe(input);
+        expect(input).toHaveProperty('value', 'John');
+
+        // Clicking "Submit" selects it, after the post back.
+        await waitFor(async () =>
+          expect((await testHelpers.getAccessibilityNode(submitButton)).description?.value).toBe('Selected')
+        );
+
+        // THEN: The card shows "John" in the input.
+        await host.snapshot('local');
+      });
+    </script>
+  </body>
+</html>
diff --git a/__tests__/html2/react19/strictMode.adaptiveCard.submit.html.snap-1.png b/__tests__/html2/react19/strictMode.adaptiveCard.submit.html.snap-1.png
new file mode 100644
index 0000000000..42d3b6c48d
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diff --git a/__tests__/html2/react19/strictMode.esm.html b/__tests__/html2/react19/strictMode.esm.html
new file mode 100644
index 0000000000..28ae00b4f4
--- /dev/null
+++ b/__tests__/html2/react19/strictMode.esm.html
@@ -0,0 +1,198 @@
+<!doctype html>
+<html lang="en-US">
+  <head>
+    <title>React 19 in Strict Mode (ESM build): message, carousel, suggested action and Adaptive Card</title>
+    <link href="/assets/index.css" rel="stylesheet" type="text/css" />
+  </head>
+  <body>
+    <main id="webchat"></main>
+    <script type="importmap">
+      {
+        "imports": {
+          "@testduet/wait-for": "https://esm.sh/@testduet/wait-for",
+          "botframework-webchat": "/__dist__/packages/bundle/static/botframework-webchat.js",
+          "react": "https://esm.sh/react@19.3.1?dev",
+          "react-dom": "https://esm.sh/react-dom@19.3.1?dev",
+          "react-dom/client": "https://esm.sh/react-dom@19.3.1/client?dev"
+        }
+      }
+    </script>
+    <script type="module">
+      import '/test-harness.mjs';
+      import '/test-page-object.mjs';
+
+      import { waitFor } from '@testduet/wait-for';
+      import { createStoreWithOptions, ReactWebChat, testIds } from 'botframework-webchat';
+      import { createElement, StrictMode, useEffect, version } from 'react';
+      import { createRoot } from 'react-dom/client';
+
+      run(async function () {
+        // TODO: This is for `createDirectLineEmulator` and `pageElements` only, should find ways to eliminate this line.
+        window.WebChat = { createStoreWithOptions, testIds };
+
+        const { directLine, store } = testHelpers.createDirectLineEmulator();
+        let numMounts = 0;
+
+        const MountCounter = () => {
+          useEffect(() => {
+            numMounts++;
+          }, []);
+
+          return null;
+        };
+
+        // GIVEN: The development build of React 19, which runs the checks of Strict Mode.
+        expect(version).toBe('19.3.1');
+
+        // WHEN: Web Chat is rendered in Strict Mode.
+        createRoot(document.getElementById('webchat')).render(
+          createElement(StrictMode, {}, createElement(MountCounter), createElement(ReactWebChat, { directLine, store }))
+        );
+
+        // THEN: Strict Mode should mount, unmount, and mount again.
+        await waitFor(() => expect(numMounts).toBe(2));
+
+        await pageConditions.uiConnected();
+
+        // WHEN: The user types a message and presses ENTER.
+        const { activity: typedActivity, resolveAll: resolveTypedActivity } = await directLine.actPostActivity(
+          async () => {
+            await host.click(pageElements.sendBoxTextBox());
+            await host.sendKeys('Hello, World!', 'ENTER');
+
+            await pageConditions.numActivitiesShown(1);
+          }
+        );
+
+        await resolveTypedActivity();
+
+        expect(typedActivity).toHaveProperty('text', 'Hello, World!');
+
+        const createHeroCard = index => ({
+          content: { title: `Item ${index}` },
+          contentType: 'application/vnd.microsoft.card.hero'
+        });
+
+        // WHEN: The bot replies with a carousel of 3 cards and a suggested action.
+        await directLine.emulateIncomingActivity({
+          attachmentLayout: 'carousel',
+          attachments: [createHeroCard(1), createHeroCard(2), createHeroCard(3)],
+          suggestedActions: { actions: [{ title: 'USA', type: 'imBack', value: 'USA' }] },
+          text: 'Where are you from?'
+        });
+
+        await pageConditions.numActivitiesShown(2);
+        await pageConditions.suggestedActionsShown();
+
+        const carouselLayout = document.querySelector('.carousel-layout');
+        const carouselFilmstrip = carouselLayout.querySelector('.carousel-filmstrip');
+        const flippers = Array.from(carouselLayout.querySelectorAll('.react-film__flipper'));
+
+        // The flipper is hidden when its body has slid out of the flipper button (1s delay after hover or scroll ends, then 300ms slide).
+        const isFlipperHidden = flipper => {
+          const bodyRect = flipper.querySelector('.react-film__flipper__body').getBoundingClientRect();
+          const buttonRect = flipper.getBoundingClientRect();
+
+          return bodyRect.right <= buttonRect.left || bodyRect.left >= buttonRect.right;
+        };
+
+        const waitForCarouselSettled = () =>
+          waitFor(
+            () => {
+              expect(carouselLayout.querySelector('.react-film__main--scrolling')).toBeNull();
+              expect(flippers.every(isFlipperHidden)).toBe(true);
+            },
+            { timeout: 5000 }
+          );
+
+        expect(carouselFilmstrip.scrollLeft).toBe(0);
+
+        await waitForCarouselSettled();
+        await pageConditions.scrollStabilized();
+
+        // THEN: "Hello, World!" is sent, the bot shows the carousel at its first card and the "USA" suggested action.
+        await host.snapshot('local');
+
+        // WHEN: The "Next" flipper of the carousel is clicked, then the mouse leaves the carousel.
+        await host.click(carouselLayout.querySelector('[aria-label="Next"]'));
+        await waitFor(() => expect(carouselFilmstrip.scrollLeft).toBeGreaterThan(0));
+        await host.hover(pageElements.sendBoxTextBox());
+
+        await waitForCarouselSettled();
+
+        // THEN: The carousel is scrolled away from its first card.
+        await host.snapshot('local');
+
+        const carouselScrollLeft = carouselFilmstrip.scrollLeft;
+
+        // WHEN: The user clicks the suggested action.
+        const { activity: clickedActivity, resolveAll: resolveClickedActivity } = await directLine.actPostActivity(
+          async () => {
+            await pageObjects.clickNthSuggestedAction(1);
+            await pageConditions.numActivitiesShown(3);
+          }
+        );
+
+        await resolveClickedActivity();
+
+        expect(clickedActivity).toHaveProperty('text', 'USA');
+
+        await waitFor(() => expect(pageElements.suggestedActions()).toHaveLength(0));
+        await pageConditions.scrollStabilized();
+
+        // The carousel keeps its position.
+        expect(document.querySelector('.carousel-layout .carousel-filmstrip').scrollLeft).toBe(carouselScrollLeft);
+
+        // THEN: "USA" is sent and the suggested action is gone.
+        await host.snapshot('local');
+
+        // WHEN: The bot sends an Adaptive Card with a text input and a "Submit" button without `data`, which sends the inputs as a post back.
+        await directLine.emulateIncomingActivity({
+          attachments: [
+            {
+              content: {
+                $schema: 'http://adaptivecards.io/schemas/adaptive-card.json',
+                actions: [{ title: 'Submit', type: 'Action.Submit' }],
+                body: [{ id: 'firstName', label: 'First name', type: 'Input.Text' }],
+                type: 'AdaptiveCard',
+                version: '1.3'
+              },
+              contentType: 'application/vnd.microsoft.card.adaptive'
+            }
+          ],
+          from: { role: 'bot' },
+          type: 'message'
+        });
+
+        await pageConditions.numActivitiesShown(4);
+
+        const input = document.querySelector('.ac-textInput input, input.ac-textInput');
+        const submitButton = document.querySelector('.ac-pushButton');
+
+        // WHEN: "John" is typed into the input and the "Submit" button is clicked.
+        await host.click(input);
+        await host.sendKeys('John');
+
+        const { activity: submittedActivity, resolveAll: resolveSubmittedActivity } = await directLine.actPostActivity(
+          () => host.click(submitButton)
+        );
+
+        await resolveSubmittedActivity();
+
+        // THEN: The post back should have the typed value.
+        expect(submittedActivity).toHaveProperty('value', { firstName: 'John' });
+
+        // Clicking "Submit" selects it, after the post back.
+        await waitFor(async () =>
+          expect((await testHelpers.getAccessibilityNode(submitButton)).description?.value).toBe('Selected')
+        );
+
+        await pageConditions.scrollStabilized();
+
+        // THEN: The card shows "John" in the input.
+        // `run()` ends with `host.done()`, which fails on any `console.error`, where React 19 logs its development warnings.
+        await host.snapshot('local');
+      });
+    </script>
+  </body>
+</html>
diff --git a/__tests__/html2/react19/strictMode.esm.html.snap-1.png b/__tests__/html2/react19/strictMode.esm.html.snap-1.png
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diff --git a/__tests__/html2/react19/strictMode.esm.html.snap-2.png b/__tests__/html2/react19/strictMode.esm.html.snap-2.png
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index 0000000000..24d28e598b
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diff --git a/__tests__/html2/react19/strictMode.esm.html.snap-3.png b/__tests__/html2/react19/strictMode.esm.html.snap-3.png
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diff --git a/__tests__/html2/react19/strictMode.esm.html.snap-4.png b/__tests__/html2/react19/strictMode.esm.html.snap-4.png
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diff --git a/__tests__/html2/strictMode/adaptiveCard.submit.html b/__tests__/html2/strictMode/adaptiveCard.submit.html
new file mode 100644
index 0000000000..523956d52f
--- /dev/null
+++ b/__tests__/html2/strictMode/adaptiveCard.submit.html
@@ -0,0 +1,98 @@
+<!doctype html>
+<html lang="en-US">
+  <head>
+    <title>Strict Mode: submits the typed value of an Adaptive Card on React 18</title>
+    <link href="/assets/index.css" rel="stylesheet" type="text/css" />
+  </head>
+  <body>
+    <main id="webchat"></main>
+    <script type="importmap">
+      {
+        "imports": {
+          "@testduet/wait-for": "https://esm.sh/@testduet/wait-for",
+          "botframework-webchat": "/__dist__/packages/bundle/static/botframework-webchat.js",
+          "react": "/__dist__/packages/bundle/static/react.js",
+          "react-dom": "/__dist__/packages/bundle/static/react-dom.js",
+          "react-dom/client": "/__dist__/packages/bundle/static/react-dom/client.js"
+        }
+      }
+    </script>
+    <script type="module">
+      import '/test-harness.mjs';
+      import '/test-page-object.mjs';
+
+      import { waitFor } from '@testduet/wait-for';
+      import { createStoreWithOptions, ReactWebChat } from 'botframework-webchat';
+      import { createElement, StrictMode, version } from 'react';
+      import { createRoot } from 'react-dom/client';
+
+      run(async function () {
+        // TODO: This is for `createDirectLineEmulator` only, should find ways to eliminate this line.
+        window.WebChat = { createStoreWithOptions };
+
+        const { directLine, store } = testHelpers.createDirectLineEmulator();
+
+        // GIVEN: The development build of React 18, which renders twice in Strict Mode (React 19: react19/strictMode.adaptiveCard.submit.html).
+        expect(version).toBe('18.3.1');
+
+        createRoot(document.getElementById('webchat')).render(
+          createElement(
+            StrictMode,
+            {},
+            createElement(ReactWebChat, { directLine, store, styleOptions: { hideSendBox: true } })
+          )
+        );
+
+        await pageConditions.uiConnected();
+
+        // GIVEN: A card with a text input and a "Submit" button without `data`, which sends the inputs as a post back.
+        await directLine.emulateIncomingActivity({
+          attachments: [
+            {
+              content: {
+                $schema: 'http://adaptivecards.io/schemas/adaptive-card.json',
+                actions: [{ title: 'Submit', type: 'Action.Submit' }],
+                body: [{ id: 'firstName', label: 'First name', type: 'Input.Text' }],
+                type: 'AdaptiveCard',
+                version: '1.3'
+              },
+              contentType: 'application/vnd.microsoft.card.adaptive'
+            }
+          ],
+          from: { role: 'bot' },
+          type: 'message'
+        });
+
+        await pageConditions.numActivitiesShown(1);
+
+        const input = document.querySelector('.ac-textInput input, input.ac-textInput');
+        const submitButton = document.querySelector('.ac-pushButton');
+
+        expect(submitButton).toHaveProperty('textContent', 'Submit');
+
+        // WHEN: "John" is typed into the input and the "Submit" button is clicked.
+        await host.click(input);
+        await host.sendKeys('John');
+
+        const { activity, resolveAll } = await directLine.actPostActivity(() => host.click(submitButton));
+
+        await resolveAll();
+
+        // THEN: The post back should have the typed value.
+        expect(activity).toHaveProperty('value', { firstName: 'John' });
+
+        // THEN: The input on screen should be the one the card read.
+        expect(document.querySelector('.ac-textInput input, input.ac-textInput')).toBe(input);
+        expect(input).toHaveProperty('value', 'John');
+
+        // Clicking "Submit" selects it, after the post back.
+        await waitFor(async () =>
+          expect((await testHelpers.getAccessibilityNode(submitButton)).description?.value).toBe('Selected')
+        );
+
+        // THEN: The card shows "John" in the input.
+        await host.snapshot('local');
+      });
+    </script>
+  </body>
+</html>
diff --git a/__tests__/html2/strictMode/adaptiveCard.submit.html.snap-1.png b/__tests__/html2/strictMode/adaptiveCard.submit.html.snap-1.png
new file mode 100644
index 0000000000..42d3b6c48d
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diff --git a/docs/HOSTING.md b/docs/HOSTING.md
index b100dabca3..d4d9d913b9 100644
--- a/docs/HOSTING.md
+++ b/docs/HOSTING.md
@@ -87,12 +87,12 @@ Serving Web Chat code from your own service is recommended for these environment
 
 For React web apps, it is important to have all React components rendered with the same version and instance of the React runtime.
 
-To choose between different version of React runtime, modify the import map and reference the version of your choice. React runtime must be loaded as ES Modules (ESM) instead of UMD. You may need to use a smart CDN service to load React runtime as ESM.
+Web Chat supports React 16.8.6 to 19. To choose between different version of React runtime, modify the import map and reference the version of your choice. React runtime must be loaded as ES Modules (ESM) instead of UMD. You may need to use a smart CDN service to load React runtime as ESM.
 
-When deploying to locked down environment, clients may not have access to smart CDN service. For conveniences, Web Chat repacked React 16.8.6 (baseline) and React 18 (latest supported) as ESM under the `/static/` directory.
+When deploying to locked down environment, clients may not have access to smart CDN service. For conveniences, Web Chat repacked React 16.8.6 (baseline) and React 18 as ESM under the `/static/` directory.
 
 <details>
-<summary>For React (latest supported)</summary>
+<summary>For React 18</summary>
 
 ```html
 <script type="importmap">
diff --git a/package-lock.json b/package-lock.json
index ce9c6e540e..f06af860de 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -21192,7 +21192,6 @@
         "globalize": "1.7.1",
         "iter-fest": "0.3.1",
         "math-random": "2.0.1",
-        "prop-types": "15.8.1",
         "react-chain-of-responsibility": "0.4.2",
         "redux": "5.0.1",
         "simple-update-in": "2.2.0",
@@ -21436,7 +21435,6 @@
         "micromark-util-character": "2.1.1",
         "micromark-util-sanitize-uri": "2.0.1",
         "microsoft-cognitiveservices-speech-sdk": "1.50.0",
-        "prop-types": "15.8.1",
         "punycode": "2.3.1",
         "sanitize-html": "2.17.4",
         "shiki": "2.5.0",
@@ -22033,7 +22031,6 @@
         "memoize-one": "6.0.0",
         "merge-refs": "2.0.0",
         "micromark": "4.0.2",
-        "prop-types": "15.8.1",
         "punycode": "2.3.1",
         "react-chain-of-responsibility": "0.4.2",
         "react-dictate-button": "4.0.1",
@@ -29885,7 +29882,6 @@
         "event-target-shim": "6.0.2",
         "math-random": "2.0.1",
         "microsoft-cognitiveservices-speech-sdk": "1.50.0",
-        "prop-types": "15.8.1",
         "simple-update-in": "2.2.0"
       },
       "devDependencies": {
diff --git a/packages/api/package.json b/packages/api/package.json
index 690c37bba0..88207a9bc2 100644
--- a/packages/api/package.json
+++ b/packages/api/package.json
@@ -205,7 +205,6 @@
     "globalize": "1.7.1",
     "iter-fest": "0.3.1",
     "math-random": "2.0.1",
-    "prop-types": "15.8.1",
     "react-chain-of-responsibility": "0.4.2",
     "redux": "5.0.1",
     "simple-update-in": "2.2.0",
diff --git a/packages/api/src/hooks/Composer.tsx b/packages/api/src/hooks/Composer.tsx
index 11678f3d22..8e666f64a4 100644
--- a/packages/api/src/hooks/Composer.tsx
+++ b/packages/api/src/hooks/Composer.tsx
@@ -40,7 +40,6 @@ import {
   type GlobalScopePonyfill,
   type WebChatActivity
 } from 'botframework-webchat-core';
-import PropTypes from 'prop-types';
 import React, { useCallback, useEffect, useMemo, useRef, useState, type ReactNode } from 'react';
 import updateIn from 'simple-update-in';
 
@@ -709,47 +708,6 @@ const ComposerCore = ({
  *       We should decide which data is needed for React but not in other environment such as CLI/VSCode
  */
 
-ComposerCore.propTypes = {
-  activityStatusMiddleware: PropTypes.oneOfType([PropTypes.arrayOf(PropTypes.func), PropTypes.func]),
-  attachmentForScreenReaderMiddleware: PropTypes.oneOfType([PropTypes.arrayOf(PropTypes.func), PropTypes.func]),
-  attachmentMiddleware: PropTypes.oneOfType([PropTypes.arrayOf(PropTypes.func), PropTypes.func]),
-  avatarMiddleware: PropTypes.oneOfType([PropTypes.arrayOf(PropTypes.func), PropTypes.func]),
-  cardActionMiddleware: PropTypes.oneOfType([PropTypes.arrayOf(PropTypes.func), PropTypes.func]),
-  children: PropTypes.any,
-  dir: PropTypes.oneOf(['auto', 'ltr', 'rtl']),
-  // PropTypes.shape({ ... }) did not honor isRequired for its members.
-  // @ts-ignore
-  directLine: PropTypes.shape({
-    activity$: PropTypes.shape({
-      subscribe: PropTypes.func.isRequired
-    }).isRequired,
-    connectionStatus$: PropTypes.shape({
-      subscribe: PropTypes.func.isRequired
-    }).isRequired,
-    end: PropTypes.func,
-    getSessionId: PropTypes.func,
-    postActivity: PropTypes.func.isRequired,
-    referenceGrammarID: PropTypes.string,
-    token: PropTypes.string
-  }).isRequired,
-  disabled: PropTypes.bool,
-  downscaleImageToDataURL: PropTypes.func,
-  grammars: PropTypes.arrayOf(PropTypes.string),
-  groupActivitiesMiddleware: PropTypes.oneOfType([PropTypes.arrayOf(PropTypes.func), PropTypes.func]),
-  locale: PropTypes.string,
-  onTelemetry: PropTypes.func,
-  overrideLocalizedStrings: PropTypes.oneOfType([PropTypes.any, PropTypes.func]),
-  renderMarkdown: PropTypes.func,
-  scrollToEndButtonMiddleware: PropTypes.oneOfType([PropTypes.arrayOf(PropTypes.func), PropTypes.func]),
-  selectVoice: PropTypes.func,
-  sendTypingIndicator: PropTypes.bool,
-  toastMiddleware: PropTypes.oneOfType([PropTypes.arrayOf(PropTypes.func), PropTypes.func]),
-  typingIndicatorMiddleware: PropTypes.oneOfType([PropTypes.arrayOf(PropTypes.func), PropTypes.func]),
-  uiState: PropTypes.oneOf(['blueprint', 'disabled']),
-  userID: PropTypes.string,
-  username: PropTypes.string
-};
-
 type ComposerWithStoreProps = ComposerCoreProps &
   Readonly<{
     store?: any;
@@ -825,11 +783,6 @@ const ComposerWithStore = ({ onTelemetry, store, ...props }: ComposerWithStorePr
   );
 };
 
-ComposerWithStore.propTypes = {
-  onTelemetry: PropTypes.func,
-  store: PropTypes.any
-};
-
 const Composer = ({ internalRenderErrorBox, onTelemetry, ponyfill, styleOptions, ...props }: ComposerProps) => {
   const [error, setError] = useState();
 
diff --git a/packages/api/src/hooks/middleware/UserlandBoundary.js b/packages/api/src/hooks/middleware/UserlandBoundary.js
index b2af952a73..4656dee6c9 100644
--- a/packages/api/src/hooks/middleware/UserlandBoundary.js
+++ b/packages/api/src/hooks/middleware/UserlandBoundary.js
@@ -1,5 +1,4 @@
 import { ErrorBoxPolymiddlewareProxy } from '@msinternal/botframework-webchat-api-middleware';
-import PropTypes from 'prop-types';
 import React, { useCallback, useState } from 'react';
 
 import ErrorBoundary from '../utils/ErrorBoundary';
@@ -16,9 +15,4 @@ const UserlandBoundary = ({ children, type }) => {
   );
 };
 
-UserlandBoundary.propTypes = {
-  children: PropTypes.any,
-  type: PropTypes.string
-};
-
 export default UserlandBoundary;
diff --git a/packages/api/src/hooks/utils/ErrorBoundary.js b/packages/api/src/hooks/utils/ErrorBoundary.js
index 229fbd489b..cfc1350a73 100644
--- a/packages/api/src/hooks/utils/ErrorBoundary.js
+++ b/packages/api/src/hooks/utils/ErrorBoundary.js
@@ -1,5 +1,4 @@
 import React, { Component } from 'react';
-import PropTypes from 'prop-types';
 
 const RenderChildrenFunction = ({ children }) => (typeof children === 'function' ? children() : children);
 
@@ -26,14 +25,4 @@ class ErrorBoundary extends Component {
   }
 }
 
-ErrorBoundary.defaultProps = {
-  children: undefined,
-  onError: undefined
-};
-
-ErrorBoundary.propTypes = {
-  children: PropTypes.any,
-  onError: PropTypes.func
-};
-
 export default ErrorBoundary;
diff --git a/packages/api/src/providers/Ponyfill/PonyfillComposer.tsx b/packages/api/src/providers/Ponyfill/PonyfillComposer.tsx
index 6acf25e9ac..97a79e8da6 100644
--- a/packages/api/src/providers/Ponyfill/PonyfillComposer.tsx
+++ b/packages/api/src/providers/Ponyfill/PonyfillComposer.tsx
@@ -1,12 +1,11 @@
 import type { GlobalScopePonyfill } from 'botframework-webchat-core';
-import PropTypes from 'prop-types';
 import React, { useMemo, useRef, type PropsWithChildren } from 'react';
 
 import type { ContextOf } from '../../types/ContextOf';
 import PonyfillContext from './private/PonyfillContext';
 
 type Props = PropsWithChildren<{
-  ponyfill?: Partial<GlobalScopePonyfill>;
+  readonly ponyfill?: Partial<GlobalScopePonyfill> | undefined;
 }>;
 
 const PonyfillComposer = ({ children, ponyfill: partialPonyfill }: Props) => {
@@ -85,8 +84,4 @@ const PonyfillComposer = ({ children, ponyfill: partialPonyfill }: Props) => {
   return <PonyfillContext.Provider value={contextValue}>{children}</PonyfillContext.Provider>;
 };
 
-PonyfillComposer.propTypes = {
-  ponyfill: PropTypes.any
-};
-
 export default PonyfillComposer;
diff --git a/packages/bundle/package.json b/packages/bundle/package.json
index c42d079301..5bdb4d2f8a 100644
--- a/packages/bundle/package.json
+++ b/packages/bundle/package.json
@@ -287,7 +287,6 @@
     "micromark-util-character": "2.1.1",
     "micromark-util-sanitize-uri": "2.0.1",
     "microsoft-cognitiveservices-speech-sdk": "1.50.0",
-    "prop-types": "15.8.1",
     "punycode": "2.3.1",
     "sanitize-html": "2.17.4",
     "shiki": "2.5.0",
diff --git a/packages/bundle/src/FullComposer.tsx b/packages/bundle/src/FullComposer.tsx
index eb74cf6501..fb1cb50066 100644
--- a/packages/bundle/src/FullComposer.tsx
+++ b/packages/bundle/src/FullComposer.tsx
@@ -15,13 +15,11 @@ type FullComposerProps = Omit<BaseFullComposerProps, 'children'> & {
   readonly children?: ComposerPropsChildren | AddFullBundleChildren | undefined;
 };
 
-const FullComposer = (props: FullComposerProps) => (
+const FullComposer = ({ children, ...props }: FullComposerProps) => (
   <AddFullBundle {...props}>
     {extraProps => (
       <Composer {...props} {...extraProps}>
-        {/* We need to spread, thus, we cannot we destructuring assignment. */}
-        {/* eslint-disable-next-line react/destructuring-assignment */}
-        {props.children}
+        {typeof children === 'function' ? children(extraProps) : children}
       </Composer>
     )}
   </AddFullBundle>
diff --git a/packages/bundle/src/adaptiveCards/Attachment/AdaptiveCardHacks/private/useAdaptiveCardModEffect.ts b/packages/bundle/src/adaptiveCards/Attachment/AdaptiveCardHacks/private/useAdaptiveCardModEffect.ts
index 5b79976eca..3fed8831d5 100644
--- a/packages/bundle/src/adaptiveCards/Attachment/AdaptiveCardHacks/private/useAdaptiveCardModEffect.ts
+++ b/packages/bundle/src/adaptiveCards/Attachment/AdaptiveCardHacks/private/useAdaptiveCardModEffect.ts
@@ -48,7 +48,7 @@ export default function useAdaptiveCardModEffect<TArgs extends unknown[]>(
 ): readonly [(cardElement: HTMLElement, ...args: TArgs) => void, () => void] {
   const adaptiveCardRef = useValueRef(adaptiveCard);
   const mod = useMemo(() => new Mod<TArgs>(modder), [modder]);
-  const reapplyRef = useRef<() => void>();
+  const reapplyRef = useRef<(() => void) | undefined>(undefined);
 
   const observerRef = useLazyRef<MutationObserver>(
     () =>
diff --git a/packages/bundle/src/adaptiveCards/Attachment/AdaptiveCardHacks/private/usePrevious.ts b/packages/bundle/src/adaptiveCards/Attachment/AdaptiveCardHacks/private/usePrevious.ts
index 5939e99473..ad663e86e0 100644
--- a/packages/bundle/src/adaptiveCards/Attachment/AdaptiveCardHacks/private/usePrevious.ts
+++ b/packages/bundle/src/adaptiveCards/Attachment/AdaptiveCardHacks/private/usePrevious.ts
@@ -2,7 +2,7 @@
 import { useEffect, useRef } from 'react';
 
 export default function usePrevious<T>(value: T): T | undefined {
-  const ref = useRef<T>();
+  const ref = useRef<T | undefined>(undefined);
 
   useEffect(() => {
     ref.current = value;
diff --git a/packages/bundle/src/adaptiveCards/Attachment/AdaptiveCardHacks/useActionShouldBePushButtonModEffect.ts b/packages/bundle/src/adaptiveCards/Attachment/AdaptiveCardHacks/useActionShouldBePushButtonModEffect.ts
index 42640af7c5..5cca332024 100644
--- a/packages/bundle/src/adaptiveCards/Attachment/AdaptiveCardHacks/useActionShouldBePushButtonModEffect.ts
+++ b/packages/bundle/src/adaptiveCards/Attachment/AdaptiveCardHacks/useActionShouldBePushButtonModEffect.ts
@@ -35,7 +35,7 @@ export default function useActionShouldBePushButtonModEffect(
   () => void,
   (action: CardObject) => boolean
 ] {
-  const markActionAsSelectedRef = useRef<((action: CardObject) => boolean) | undefined>();
+  const markActionAsSelectedRef = useRef<((action: CardObject) => boolean) | undefined>(undefined);
   const prevAdaptiveCard = usePrevious(adaptiveCard);
   const pushedCardObjectsRef = useRef<Set<CardObject>>(new Set());
 
diff --git a/packages/bundle/src/adaptiveCards/Attachment/AdaptiveCardHacks/useActiveElementModEffect.ts b/packages/bundle/src/adaptiveCards/Attachment/AdaptiveCardHacks/useActiveElementModEffect.ts
index e47c49a4d9..e33c87088a 100644
--- a/packages/bundle/src/adaptiveCards/Attachment/AdaptiveCardHacks/useActiveElementModEffect.ts
+++ b/packages/bundle/src/adaptiveCards/Attachment/AdaptiveCardHacks/useActiveElementModEffect.ts
@@ -10,7 +10,7 @@ import type { AdaptiveCard, CardObject } from 'adaptivecards';
  * Re-rendering: Last focused element must be persisted during render cycle.
  */
 export default function useActiveElementModEffect(adaptiveCard: AdaptiveCard) {
-  const activeCardObjectRef = useRef<CardObject | undefined>();
+  const activeCardObjectRef = useRef<CardObject | undefined>(undefined);
   const prevAdaptiveCard = usePrevious(adaptiveCard);
 
   if (prevAdaptiveCard !== adaptiveCard) {
diff --git a/packages/bundle/src/adaptiveCards/Attachment/AdaptiveCardRenderer.tsx b/packages/bundle/src/adaptiveCards/Attachment/AdaptiveCardRenderer.tsx
index 53e40b6b8c..0dde8bb084 100644
--- a/packages/bundle/src/adaptiveCards/Attachment/AdaptiveCardRenderer.tsx
+++ b/packages/bundle/src/adaptiveCards/Attachment/AdaptiveCardRenderer.tsx
@@ -52,6 +52,11 @@ const adaptiveCardRendererPropsSchema = pipe(
 
 type AdaptiveCardRendererProps = InferInput<typeof adaptiveCardRendererPropsSchema>;
 
+type AdaptiveCardRenderResult = {
+  readonly element?: HTMLElement | undefined;
+  readonly errors?: readonly Error[] | undefined;
+};
+
 function AdaptiveCardRenderer(props: AdaptiveCardRendererProps) {
   const {
     actionPerformedClassName,
@@ -64,7 +69,7 @@ function AdaptiveCardRenderer(props: AdaptiveCardRendererProps) {
   const [{ GlobalSettings, HostConfig }] = useAdaptiveCardsPackage();
   const [adaptiveCardsHostConfig] = useAdaptiveCardsHostConfig();
   const [uiState] = useUIState();
-  const contentRef = useRef<HTMLDivElement>();
+  const contentRef = useRef<HTMLDivElement>(null);
   const localize = useLocalizer();
   const performCardAction = usePerformCardAction();
   const queueStaticElement = useQueueStaticElement();
@@ -222,7 +227,28 @@ function AdaptiveCardRenderer(props: AdaptiveCardRendererProps) {
   // For accessibility issue #1340, `tabindex="0"` must not be set for the root container if it is not interactive.
   const setTabIndexAtCardRoot = !!tapAction;
 
-  const { element, errors }: { element?: HTMLElement; errors?: Error[] } = useMemo(() => {
+  const lastRenderRef = useRef<
+    { readonly inputs: readonly unknown[]; readonly result: AdaptiveCardRenderResult } | undefined
+  >(undefined);
+
+  const { element, errors } = useMemo<AdaptiveCardRenderResult>(() => {
+    const inputs = Object.freeze([
+      adaptiveCard,
+      adaptiveCardsHostConfig,
+      GlobalSettings,
+      HostConfig,
+      renderMarkdownAsHTML,
+      setTabIndexAtCardRoot
+    ]);
+
+    const { current: lastRender } = lastRenderRef;
+
+    // Render the card once per inputs: the card reads its inputs from the DOM of its last render.
+    // React 19 in Strict Mode calls `useMemo()` twice and keeps the first result, the inputs on screen would be detached from the card.
+    if (lastRender && lastRender.inputs.every((value, index) => Object.is(value, inputs.at(index)))) {
+      return lastRender.result;
+    }
+
     undoActionShouldBePushButtonMod();
     undoActiveElementMod();
     undoDisabledMod();
@@ -230,12 +256,18 @@ function AdaptiveCardRenderer(props: AdaptiveCardRendererProps) {
     undoPersistValuesMod();
     undoRoleMod();
 
-    return renderAdaptiveCard(adaptiveCard, {
-      adaptiveCardsHostConfig,
-      adaptiveCardsPackage: { GlobalSettings, HostConfig },
-      renderMarkdownAsHTML,
-      setTabIndexAtCardRoot
-    });
+    const result: AdaptiveCardRenderResult = Object.freeze(
+      renderAdaptiveCard(adaptiveCard, {
+        adaptiveCardsHostConfig,
+        adaptiveCardsPackage: { GlobalSettings, HostConfig },
+        renderMarkdownAsHTML,
+        setTabIndexAtCardRoot
+      })
+    );
+
+    lastRenderRef.current = Object.freeze({ inputs, result });
+
+    return result;
   }, [
     adaptiveCard,
     adaptiveCardsHostConfig,
diff --git a/packages/bundle/src/adaptiveCards/AttachmentForScreenReader/AdaptiveCardAttachment.js b/packages/bundle/src/adaptiveCards/AttachmentForScreenReader/AdaptiveCardAttachment.js
index 90157117a7..6dca0ad55a 100644
--- a/packages/bundle/src/adaptiveCards/AttachmentForScreenReader/AdaptiveCardAttachment.js
+++ b/packages/bundle/src/adaptiveCards/AttachmentForScreenReader/AdaptiveCardAttachment.js
@@ -3,7 +3,6 @@
 import { hooks } from 'botframework-webchat-component';
 import { htmlTextAlternatives } from 'botframework-webchat-component/internal.js';
 import { onErrorResumeNext } from 'botframework-webchat-core';
-import PropTypes from 'prop-types';
 import React, { useMemo } from 'react';
 
 import setMarkdownEngine from '../Attachment/private/setMarkdownEngine';
@@ -82,20 +81,6 @@ const AdaptiveCardChoiceSetInput = ({ input: { choices, defaultValue, label } })
   );
 };
 
-AdaptiveCardChoiceSetInput.propTypes = {
-  input: PropTypes.shape({
-    choices: PropTypes.arrayOf(
-      PropTypes.shape({
-        title: PropTypes.string,
-        value: PropTypes.any
-      })
-    ),
-    defaultValue: PropTypes.any,
-    label: PropTypes.string,
-    value: PropTypes.any
-  }).isRequired
-};
-
 const AdaptiveCardAttachment = ({ content }) => {
   const localize = useLocalizer();
   const parseAdaptiveCardJSON = useParseAdaptiveCardJSON();
@@ -242,8 +227,4 @@ const AdaptiveCardAttachment = ({ content }) => {
   );
 };
 
-AdaptiveCardAttachment.propTypes = {
-  content: PropTypes.any.isRequired
-};
-
 export default AdaptiveCardAttachment;
diff --git a/packages/bundle/src/adaptiveCards/AttachmentForScreenReader/RichCardAttachment.js b/packages/bundle/src/adaptiveCards/AttachmentForScreenReader/RichCardAttachment.js
index 16e6b5db0c..c5c21468bf 100644
--- a/packages/bundle/src/adaptiveCards/AttachmentForScreenReader/RichCardAttachment.js
+++ b/packages/bundle/src/adaptiveCards/AttachmentForScreenReader/RichCardAttachment.js
@@ -1,5 +1,4 @@
 /* eslint-disable react/no-array-index-key */
-import PropTypes from 'prop-types';
 import React from 'react';
 import { hooks } from 'botframework-webchat-component';
 
@@ -72,8 +71,4 @@ const RichCardAttachment = ({ content = {} }) => {
   );
 };
 
-RichCardAttachment.propTypes = {
-  content: PropTypes.any.isRequired
-};
-
 export default RichCardAttachment;
diff --git a/packages/bundle/test-d/pass/composition-with-store.test-d.tsx b/packages/bundle/test-d/pass/composition-with-store.test-d.tsx
index 819a0bfbc1..9715b41cbf 100644
--- a/packages/bundle/test-d/pass/composition-with-store.test-d.tsx
+++ b/packages/bundle/test-d/pass/composition-with-store.test-d.tsx
@@ -1,7 +1,7 @@
 import '../setup';
 
-import React from 'react';
-import ReactDOM from 'react-dom';
+import React, { type ReactElement } from 'react';
+import { expectAssignable } from 'tsd';
 
 import { Components, createStore } from '../../src/boot/exports/index';
 
@@ -9,9 +9,8 @@ const { BasicWebChat, Composer } = Components;
 
 const store = createStore({});
 
-ReactDOM.render(
+expectAssignable<ReactElement>(
   <Composer directLine={undefined} store={store}>
     <BasicWebChat />
-  </Composer>,
-  document.getElementById('app')
+  </Composer>
 );
diff --git a/packages/bundle/test-d/pass/full-composer-props-children.test-d.tsx b/packages/bundle/test-d/pass/full-composer-props-children.test-d.tsx
index 9d8c8901c2..73c5e2627f 100644
--- a/packages/bundle/test-d/pass/full-composer-props-children.test-d.tsx
+++ b/packages/bundle/test-d/pass/full-composer-props-children.test-d.tsx
@@ -4,16 +4,13 @@ import React from 'react';
 import { expectAssignable } from 'tsd';
 
 import { type FullComposerProps } from '../../src/FullComposer';
-import { type ComposerProps } from 'botframework-webchat-component';
 import { Components } from 'botframework-webchat-component';
 
-type ComposerCoreChildrenRenderProp = ComposerProps['children'];
-
 // We want to assert that `children` on FullComposerProps accepts:
 // 1. React.ReactNode
-// 2. ComposerCoreChildrenRenderProp
-// 3. AddFullBundleChildren (({ extraStyleSet }: { extraStyleSet: any }) => React.ReactNode)
+// 2. AddFullBundleChildren (({ extraStyleSet }: { extraStyleSet: any }) => React.ReactNode)
 // and is optional.
+// `Composer` renders its children as nodes: the render function `(context) => React.ReactNode` of the API `Composer` is not supported.
 
 // Helper asserting assignability.
 const expectProps = <T extends FullComposerProps>(props: T) => expectAssignable<FullComposerProps>(props);
@@ -32,20 +29,14 @@ expectProps({ directLine: mockDirectLine });
 // 2. With ReactNode child
 expectProps({ directLine: mockDirectLine, children: <div /> });
 
-// 3. With ComposerCoreChildrenRenderProp child
-// The API context type is opaque here; we just confirm it is callable.
-const composerCoreChildren: ComposerCoreChildrenRenderProp = () => <div />;
-expectProps({ directLine: mockDirectLine, children: composerCoreChildren });
-
-// 4. With AddFullBundleChildren child (takes { extraStyleSet })
+// 3. With AddFullBundleChildren child (takes { extraStyleSet })
 const addFullBundleChildren = ({ extraStyleSet }: { extraStyleSet: any }) => <div>{String(!!extraStyleSet)}</div>;
 expectProps({ directLine: mockDirectLine, children: addFullBundleChildren });
 
 // Also ensure baseline Composer (from Components) still type checks for overlapping accepted children.
 const { Composer } = Components;
 const _c1 = <Composer directLine={mockDirectLine} />;
-const _c2 = <Composer directLine={mockDirectLine}>{composerCoreChildren}</Composer>;
-const _c3 = (
+const _c2 = (
   <Composer directLine={mockDirectLine}>
     <div />
   </Composer>
diff --git a/packages/bundle/test-d/pass/render-with-store.test-d.tsx b/packages/bundle/test-d/pass/render-with-store.test-d.tsx
index 427aeb825a..a5f641eb1e 100644
--- a/packages/bundle/test-d/pass/render-with-store.test-d.tsx
+++ b/packages/bundle/test-d/pass/render-with-store.test-d.tsx
@@ -1,7 +1,7 @@
 import '../setup';
 
-import React from 'react';
-import ReactDOM from 'react-dom';
+import React, { type ReactElement } from 'react';
+import { expectAssignable } from 'tsd';
 
 import { Components, createStore } from '../../src/boot/exports/index';
 
@@ -9,4 +9,4 @@ const { Composer } = Components;
 
 const store = createStore({});
 
-ReactDOM.render(<Composer directLine={undefined} store={store} />, document.getElementById('app'));
+expectAssignable<ReactElement>(<Composer directLine={undefined} store={store} />);
diff --git a/packages/bundle/test-d/pass/render-with-style-options.test-d.tsx b/packages/bundle/test-d/pass/render-with-style-options.test-d.tsx
index 1e94d8386f..1a88e9f138 100644
--- a/packages/bundle/test-d/pass/render-with-style-options.test-d.tsx
+++ b/packages/bundle/test-d/pass/render-with-style-options.test-d.tsx
@@ -1,11 +1,11 @@
 import '../setup';
 
-import React from 'react';
-import ReactDOM from 'react-dom';
+import React, { type ReactElement } from 'react';
+import { expectAssignable } from 'tsd';
 
 import ReactWebChat, { createDirectLine } from '../../src/boot/exports/index';
 
 const directLine = createDirectLine({ token: '...' });
 const styleOptions = { accent: 'black', cardEmphasisBackgroundColor: 'orange' };
 
-ReactDOM.render(<ReactWebChat directLine={directLine} styleOptions={styleOptions} />, document.getElementById('app'));
+expectAssignable<ReactElement>(<ReactWebChat directLine={directLine} styleOptions={styleOptions} />);
diff --git a/packages/bundle/test-d/pass/render-with-style-set.test-d.tsx b/packages/bundle/test-d/pass/render-with-style-set.test-d.tsx
index aebc662bdf..0d276706bb 100644
--- a/packages/bundle/test-d/pass/render-with-style-set.test-d.tsx
+++ b/packages/bundle/test-d/pass/render-with-style-set.test-d.tsx
@@ -1,7 +1,7 @@
 import '../setup';
 
-import React from 'react';
-import ReactDOM from 'react-dom';
+import React, { type ReactElement } from 'react';
+import { expectAssignable } from 'tsd';
 
 import ReactWebChat, { createDirectLine, createStyleSet } from '../../src/boot/exports/index';
 
@@ -9,4 +9,4 @@ const directLine = createDirectLine({ token: '...' });
 const styleOptions = { accent: 'black', cardEmphasisBackgroundColor: 'orange' };
 const styleSet = createStyleSet(styleOptions);
 
-ReactDOM.render(<ReactWebChat directLine={directLine} styleSet={styleSet} />, document.getElementById('app'));
+expectAssignable<ReactElement>(<ReactWebChat directLine={directLine} styleSet={styleSet} />);
diff --git a/packages/bundle/test-d/pass/render.test-d.tsx b/packages/bundle/test-d/pass/render.test-d.tsx
index 113628483a..01e36c267f 100644
--- a/packages/bundle/test-d/pass/render.test-d.tsx
+++ b/packages/bundle/test-d/pass/render.test-d.tsx
@@ -1,10 +1,11 @@
 import '../setup';
 
-import React from 'react';
-import ReactDOM from 'react-dom';
+import React, { type ReactElement } from 'react';
+import { expectAssignable } from 'tsd';
 
 import ReactWebChat, { createDirectLine } from '../../src/boot/exports/index';
 
 const directLine = createDirectLine({ token: '...' });
 
-ReactDOM.render(<ReactWebChat directLine={directLine} />, document.getElementById('app'));
+// Not `ReactDOM.render()`: React 19 removed it, CI also checks these with @types/react@19.
+expectAssignable<ReactElement>(<ReactWebChat directLine={directLine} />);
diff --git a/packages/component/package.json b/packages/component/package.json
index 954f72c526..d1e8eb4f07 100644
--- a/packages/component/package.json
+++ b/packages/component/package.json
@@ -207,7 +207,6 @@
     "memoize-one": "6.0.0",
     "merge-refs": "2.0.0",
     "micromark": "4.0.2",
-    "prop-types": "15.8.1",
     "punycode": "2.3.1",
     "react-chain-of-responsibility": "0.4.2",
     "react-dictate-button": "4.0.1",
diff --git a/packages/component/src/Activity/CarouselFilmStrip.js b/packages/component/src/Activity/CarouselFilmStrip.js
index 39ba9e50fd..8aff49f6c7 100644
--- a/packages/component/src/Activity/CarouselFilmStrip.js
+++ b/packages/component/src/Activity/CarouselFilmStrip.js
@@ -4,7 +4,6 @@ import { hooks } from 'botframework-webchat-api';
 import { useStyles } from '@msinternal/botframework-webchat-styles/react';
 import { useItemContainerCallbackRef, useScrollableCallbackRef, useScrollTo } from 'react-film';
 import cx from 'classnames';
-import PropTypes from 'prop-types';
 import React, { useCallback } from 'react';
 
 import Bubble from './Bubble';
@@ -237,27 +236,4 @@ const CarouselFilmStrip = ({
   );
 };
 
-CarouselFilmStrip.propTypes = {
-  activity: PropTypes.shape({
-    attachments: PropTypes.array,
-    channelData: PropTypes.shape({
-      messageBack: PropTypes.shape({
-        displayText: PropTypes.string
-      })
-    }),
-    from: PropTypes.shape({
-      role: PropTypes.string.isRequired
-    }).isRequired,
-    text: PropTypes.string,
-    textFormat: PropTypes.string,
-    timestamp: PropTypes.string
-  }).isRequired,
-  className: PropTypes.string,
-  hideTimestamp: PropTypes.bool,
-  renderActivityStatus: PropTypes.oneOfType([PropTypes.oneOf([false]), PropTypes.func]),
-  renderAttachment: PropTypes.func.isRequired,
-  renderAvatar: PropTypes.oneOfType([PropTypes.oneOf([false]), PropTypes.func]),
-  showCallout: PropTypes.bool
-};
-
 export default CarouselFilmStrip;
diff --git a/packages/component/src/Activity/CarouselFilmStripAttachment.js b/packages/component/src/Activity/CarouselFilmStripAttachment.js
index 3eeafec54e..21f7f96f37 100644
--- a/packages/component/src/Activity/CarouselFilmStripAttachment.js
+++ b/packages/component/src/Activity/CarouselFilmStripAttachment.js
@@ -1,7 +1,6 @@
 import { hooks } from 'botframework-webchat-api';
 import { useStyles } from '@msinternal/botframework-webchat-styles/react';
 import cx from 'classnames';
-import PropTypes from 'prop-types';
 import React from 'react';
 
 import Bubble from './Bubble';
@@ -54,27 +53,4 @@ const CarouselFilmStripAttachment = ({
   );
 };
 
-CarouselFilmStripAttachment.propTypes = {
-  activity: PropTypes.shape({
-    attachments: PropTypes.array,
-    from: PropTypes.shape({
-      role: PropTypes.string.isRequired
-    }).isRequired,
-    text: PropTypes.string,
-    textFormat: PropTypes.string,
-    timestamp: PropTypes.string
-  }).isRequired,
-  attachment: PropTypes.shape({
-    content: PropTypes.any
-  }).isRequired,
-  className: PropTypes.string,
-  fromUser: PropTypes.any.isRequired,
-  hasAvatar: PropTypes.any.isRequired,
-  hideNub: PropTypes.bool.isRequired,
-  index: PropTypes.number.isRequired,
-  renderAttachment: PropTypes.func.isRequired,
-  showAvatar: PropTypes.bool.isRequired,
-  showNub: PropTypes.bool.isRequired
-};
-
 export default CarouselFilmStripAttachment;
diff --git a/packages/component/src/Activity/CarouselLayout.js b/packages/component/src/Activity/CarouselLayout.js
index d5164fffc5..aad58fde49 100644
--- a/packages/component/src/Activity/CarouselLayout.js
+++ b/packages/component/src/Activity/CarouselLayout.js
@@ -10,7 +10,6 @@ import {
 } from 'react-film';
 
 import cx from 'classnames';
-import PropTypes from 'prop-types';
 import React, { memo, useMemo } from 'react';
 
 import CarouselFilmStrip from './CarouselFilmStrip';
@@ -69,17 +68,6 @@ const CarouselLayoutCore = ({
   );
 };
 
-CarouselLayoutCore.propTypes = {
-  activity: PropTypes.shape({
-    attachments: PropTypes.array
-  }).isRequired,
-  hideTimestamp: PropTypes.bool,
-  renderActivityStatus: PropTypes.oneOfType([PropTypes.oneOf([false]), PropTypes.func]),
-  renderAttachment: PropTypes.func.isRequired,
-  renderAvatar: PropTypes.oneOfType([PropTypes.oneOf([false]), PropTypes.func]),
-  showCallout: PropTypes.bool
-};
-
 const CarouselLayout = props => {
   const { activity: { attachments = [] } = {} } = props;
   const [direction] = useDirection();
@@ -101,8 +89,4 @@ const CarouselLayout = props => {
   );
 };
 
-CarouselLayout.propTypes = {
-  ...CarouselLayoutCore.propTypes
-};
-
 export default memo(CarouselLayout);
diff --git a/packages/component/src/Attachment/AudioAttachment.js b/packages/component/src/Attachment/AudioAttachment.js
index d49e4f0bf8..5c276125ea 100644
--- a/packages/component/src/Attachment/AudioAttachment.js
+++ b/packages/component/src/Attachment/AudioAttachment.js
@@ -1,4 +1,3 @@
-import PropTypes from 'prop-types';
 import React from 'react';
 
 import AudioContent from './AudioContent';
@@ -14,11 +13,4 @@ const AudioAttachment = ({ attachment }) => {
   );
 };
 
-AudioAttachment.propTypes = {
-  attachment: PropTypes.shape({
-    contentUrl: PropTypes.string.isRequired,
-    name: PropTypes.string
-  }).isRequired
-};
-
 export default AudioAttachment;
diff --git a/packages/component/src/Attachment/FileAttachment.js b/packages/component/src/Attachment/FileAttachment.js
index b6fa1596b7..ff73c07868 100644
--- a/packages/component/src/Attachment/FileAttachment.js
+++ b/packages/component/src/Attachment/FileAttachment.js
@@ -1,4 +1,3 @@
-import PropTypes from 'prop-types';
 import React from 'react';
 
 import FileContent from './FileContent';
@@ -13,17 +12,4 @@ const FileAttachment = ({
   return <FileContent fileName={attachment.name} href={attachment.contentUrl} size={size} />;
 };
 
-FileAttachment.propTypes = {
-  activity: PropTypes.shape({
-    attachment: PropTypes.array,
-    channelData: PropTypes.shape({
-      attachmentSizes: PropTypes.arrayOf(PropTypes.number)
-    })
-  }).isRequired,
-  attachment: PropTypes.shape({
-    contentUrl: PropTypes.string,
-    name: PropTypes.string.isRequired
-  }).isRequired
-};
-
 export default FileAttachment;
diff --git a/packages/component/src/Attachment/VideoAttachment.js b/packages/component/src/Attachment/VideoAttachment.js
index 9e4d09f86e..fb5570c842 100644
--- a/packages/component/src/Attachment/VideoAttachment.js
+++ b/packages/component/src/Attachment/VideoAttachment.js
@@ -1,5 +1,4 @@
 import classNames from 'classnames';
-import PropTypes from 'prop-types';
 import React from 'react';
 
 import useStyleSet from '../hooks/useStyleSet';
@@ -22,11 +21,4 @@ const VideoAttachment = ({ attachment }) => {
   );
 };
 
-VideoAttachment.propTypes = {
-  attachment: PropTypes.shape({
-    contentUrl: PropTypes.string.isRequired,
-    name: PropTypes.string
-  }).isRequired
-};
-
 export default VideoAttachment;
diff --git a/packages/component/src/BasicToast.js b/packages/component/src/BasicToast.js
index 780ffe5733..045b727711 100644
--- a/packages/component/src/BasicToast.js
+++ b/packages/component/src/BasicToast.js
@@ -3,7 +3,6 @@
 
 import { hooks } from 'botframework-webchat-api';
 import classNames from 'classnames';
-import PropTypes from 'prop-types';
 import React, { useCallback, useMemo } from 'react';
 
 import ScreenReaderText from './ScreenReaderText';
@@ -70,13 +69,4 @@ const BasicToast = ({ notification: { alt, id, level, message = '' } }) => {
   );
 };
 
-BasicToast.propTypes = {
-  notification: PropTypes.shape({
-    alt: PropTypes.string,
-    id: PropTypes.string.isRequired,
-    level: PropTypes.string.isRequired,
-    message: PropTypes.string.isRequired
-  }).isRequired
-};
-
 export default BasicToast;
diff --git a/packages/component/src/Composer.tsx b/packages/component/src/Composer.tsx
index 789ae10e19..dae6b62b76 100644
--- a/packages/component/src/Composer.tsx
+++ b/packages/component/src/Composer.tsx
@@ -24,7 +24,6 @@ import { DecoratorComposer, type DecoratorMiddleware } from 'botframework-webcha
 import { type LegacyActivityMiddleware, type Polymiddleware } from 'botframework-webchat-api/middleware.js';
 import { StoreDebugAPIRegistry, type StoreDebugAPI } from 'botframework-webchat-core/internal.js';
 import classNames from 'classnames';
-import PropTypes from 'prop-types';
 import React, { memo, useCallback, useEffect, useMemo, useRef, useState, type ReactNode } from 'react';
 import { Composer as SayComposer } from 'react-say';
 
@@ -320,16 +319,8 @@ const ComposerCore = ({
   );
 };
 
-ComposerCore.propTypes = {
-  extraStyleSet: PropTypes.any,
-  nonce: PropTypes.string,
-  renderMarkdown: PropTypes.func,
-  styleSet: PropTypes.any,
-  suggestedActionsAccessKey: PropTypes.oneOfType([PropTypes.oneOf([false]), PropTypes.string]),
-  webSpeechPonyfillFactory: PropTypes.func
-};
-
-type ComposerProps = APIComposerProps & ComposerCoreProps;
+// `ComposerCore` renders `children` as nodes, the render function of the API `<Composer>` is not supported here.
+type ComposerProps = Omit<APIComposerProps, 'children'> & ComposerCoreProps;
 
 const Composer = ({
   activityMiddleware,
diff --git a/packages/component/src/ConnectivityStatus/Assets/ErrorNotificationIcon.js b/packages/component/src/ConnectivityStatus/Assets/ErrorNotificationIcon.js
index 1f3df421bd..8b9e1b2b71 100644
--- a/packages/component/src/ConnectivityStatus/Assets/ErrorNotificationIcon.js
+++ b/packages/component/src/ConnectivityStatus/Assets/ErrorNotificationIcon.js
@@ -1,6 +1,5 @@
 import { hooks } from 'botframework-webchat-api';
 import classNames from 'classnames';
-import PropTypes from 'prop-types';
 import React from 'react';
 
 const { useDirection } = hooks;
@@ -26,9 +25,4 @@ const ErrorNotificationIcon = ({ className = '', size = 1 }) => {
   );
 };
 
-ErrorNotificationIcon.propTypes = {
-  className: PropTypes.string,
-  size: PropTypes.number
-};
-
 export default ErrorNotificationIcon;
diff --git a/packages/component/src/ConnectivityStatus/Assets/WarningNotificationIcon.js b/packages/component/src/ConnectivityStatus/Assets/WarningNotificationIcon.js
index fea58b8ecf..bb3c915ec4 100644
--- a/packages/component/src/ConnectivityStatus/Assets/WarningNotificationIcon.js
+++ b/packages/component/src/ConnectivityStatus/Assets/WarningNotificationIcon.js
@@ -1,6 +1,5 @@
 import { hooks } from 'botframework-webchat-api';
 import classNames from 'classnames';
-import PropTypes from 'prop-types';
 import React from 'react';
 
 const { useDirection } = hooks;
@@ -23,9 +22,4 @@ const WarningNotificationIcon = ({ className = '', size = 1 }) => {
   );
 };
 
-WarningNotificationIcon.propTypes = {
-  className: PropTypes.string,
-  size: PropTypes.number
-};
-
 export default WarningNotificationIcon;
diff --git a/packages/component/src/Dictation.js b/packages/component/src/Dictation.js
index aaf3485569..3536b9029e 100644
--- a/packages/component/src/Dictation.js
+++ b/packages/component/src/Dictation.js
@@ -2,7 +2,6 @@ import { hooks } from 'botframework-webchat-api';
 // TODO: [P1] #3350 No import from internal, we need to move setDictateState from bf-wc-core (Redux) to React Context.
 import { useSetDictateState } from 'botframework-webchat-api/internal.js';
 import { Constants } from 'botframework-webchat-core';
-import PropTypes from 'prop-types';
 import React, { useCallback, useEffect } from 'react';
 import { Composer as DictateComposer } from 'react-dictate-button';
 
@@ -110,8 +109,4 @@ const Dictation = ({ onError }) => {
   );
 };
 
-Dictation.propTypes = {
-  onError: PropTypes.func
-};
-
 export default Dictation;
diff --git a/packages/component/src/Middleware/AttachmentForScreenReader/FileAttachment.js b/packages/component/src/Middleware/AttachmentForScreenReader/FileAttachment.js
index dfc0475f95..d925251f87 100644
--- a/packages/component/src/Middleware/AttachmentForScreenReader/FileAttachment.js
+++ b/packages/component/src/Middleware/AttachmentForScreenReader/FileAttachment.js
@@ -1,5 +1,4 @@
 import { hooks } from 'botframework-webchat-api';
-import PropTypes from 'prop-types';
 import React from 'react';
 
 const { useLocalizer } = hooks;
@@ -12,10 +11,4 @@ const FileAttachment = ({ attachment: { name = '' } = {} }) => {
   return <div role="none">{label}</div>;
 };
 
-FileAttachment.propTypes = {
-  attachment: PropTypes.shape({
-    name: PropTypes.string.isRequired
-  }).isRequired
-};
-
 export default FileAttachment;
diff --git a/packages/component/src/Middleware/AttachmentForScreenReader/TextAttachment.js b/packages/component/src/Middleware/AttachmentForScreenReader/TextAttachment.js
index ee4cc54fd0..3b24861ca8 100644
--- a/packages/component/src/Middleware/AttachmentForScreenReader/TextAttachment.js
+++ b/packages/component/src/Middleware/AttachmentForScreenReader/TextAttachment.js
@@ -1,5 +1,4 @@
 import { hooks } from 'botframework-webchat-api';
-import PropTypes from 'prop-types';
 import React from 'react';
 
 const { useLocalizer } = hooks;
@@ -12,10 +11,4 @@ const TextAttachment = ({ attachment: { content = '' } = {} }) => {
   return <div role="none">{label}</div>;
 };
 
-TextAttachment.propTypes = {
-  attachment: PropTypes.shape({
-    content: PropTypes.string.isRequired
-  }).isRequired
-};
-
 export default TextAttachment;
diff --git a/packages/component/src/SendBox/SuggestedActions.tsx b/packages/component/src/SendBox/SuggestedActions.tsx
index 43e660b86e..b0d46cfe36 100644
--- a/packages/component/src/SendBox/SuggestedActions.tsx
+++ b/packages/component/src/SendBox/SuggestedActions.tsx
@@ -2,7 +2,6 @@
 
 import { hooks } from 'botframework-webchat-api';
 import classNames from 'classnames';
-import PropTypes from 'prop-types';
 import React, { useCallback, useMemo, useRef } from 'react';
 import { createBasicStyleSet as createBasicStyleSetForReactFilm, ReactFilm } from 'react-film';
 
@@ -110,12 +109,6 @@ const SuggestedActionCarouselContainer = ({ children, className, label }) => {
   );
 };
 
-SuggestedActionCarouselContainer.propTypes = {
-  children: PropTypes.any,
-  className: PropTypes.string,
-  label: PropTypes.string.isRequired
-};
-
 const SuggestedActionFlowContainer = ({ children, className, label }) => {
   const [{ suggestedActions: suggestedActionsStyleSet }] = useStyleSet();
   const rootClassName = useStyleToEmotionObject()(ROOT_STYLE) + '';
@@ -145,12 +138,6 @@ const SuggestedActionFlowContainer = ({ children, className, label }) => {
   );
 };
 
-SuggestedActionFlowContainer.propTypes = {
-  children: PropTypes.any,
-  className: PropTypes.string,
-  label: PropTypes.string.isRequired
-};
-
 const SuggestedActionStackedContainer = ({ children, className, label }) => {
   const [{ suggestedActions: suggestedActionsStyleSet }] = useStyleSet();
   const rootClassName = useStyleToEmotionObject()(ROOT_STYLE) + '';
@@ -176,12 +163,6 @@ const SuggestedActionStackedContainer = ({ children, className, label }) => {
   );
 };
 
-SuggestedActionStackedContainer.propTypes = {
-  children: PropTypes.any,
-  className: PropTypes.string,
-  label: PropTypes.string.isRequired
-};
-
 type SuggestedActionsProps = Readonly<{
   className?: string;
 }>;
diff --git a/packages/component/src/Toast/CheckMarkIcon.js b/packages/component/src/Toast/CheckMarkIcon.js
index e0e0cbd416..22f808b921 100644
--- a/packages/component/src/Toast/CheckMarkIcon.js
+++ b/packages/component/src/Toast/CheckMarkIcon.js
@@ -1,4 +1,3 @@
-import PropTypes from 'prop-types';
 import React from 'react';
 
 const CheckMarkIcon = ({ 'aria-label': ariaLabel, className }) => (
@@ -18,9 +17,4 @@ const CheckMarkIcon = ({ 'aria-label': ariaLabel, className }) => (
   </svg>
 );
 
-CheckMarkIcon.propTypes = {
-  'aria-label': PropTypes.string,
-  className: PropTypes.string
-};
-
 export default CheckMarkIcon;
diff --git a/packages/component/src/Toast/CollapseIcon.js b/packages/component/src/Toast/CollapseIcon.js
index 0d27c83d4d..554e7de5eb 100644
--- a/packages/component/src/Toast/CollapseIcon.js
+++ b/packages/component/src/Toast/CollapseIcon.js
@@ -1,4 +1,3 @@
-import PropTypes from 'prop-types';
 import React from 'react';
 
 const CollapseIcon = ({ className }) => (
@@ -15,8 +14,4 @@ const CollapseIcon = ({ className }) => (
   </svg>
 );
 
-CollapseIcon.propTypes = {
-  className: PropTypes.string
-};
-
 export default CollapseIcon;
diff --git a/packages/component/src/Toast/DismissIcon.js b/packages/component/src/Toast/DismissIcon.js
index 617c511c83..bfd40132e7 100644
--- a/packages/component/src/Toast/DismissIcon.js
+++ b/packages/component/src/Toast/DismissIcon.js
@@ -1,4 +1,3 @@
-import PropTypes from 'prop-types';
 import React from 'react';
 
 const DismissIcon = ({ className }) => (
@@ -15,8 +14,4 @@ const DismissIcon = ({ className }) => (
   </svg>
 );
 
-DismissIcon.propTypes = {
-  className: PropTypes.string
-};
-
 export default DismissIcon;
diff --git a/packages/component/src/Toast/ExclamationMarkIcon.js b/packages/component/src/Toast/ExclamationMarkIcon.js
index 4b8e3ee44a..7556434c38 100644
--- a/packages/component/src/Toast/ExclamationMarkIcon.js
+++ b/packages/component/src/Toast/ExclamationMarkIcon.js
@@ -1,4 +1,3 @@
-import PropTypes from 'prop-types';
 import React from 'react';
 
 const ExclamationMarkIcon = ({ 'aria-label': ariaLabel, className }) => (
@@ -14,9 +13,4 @@ const ExclamationMarkIcon = ({ 'aria-label': ariaLabel, className }) => (
   </svg>
 );
 
-ExclamationMarkIcon.propTypes = {
-  'aria-label': PropTypes.string,
-  className: PropTypes.string
-};
-
 export default ExclamationMarkIcon;
diff --git a/packages/component/src/Toast/ExpandIcon.js b/packages/component/src/Toast/ExpandIcon.js
index 19e426d0b9..207453b352 100644
--- a/packages/component/src/Toast/ExpandIcon.js
+++ b/packages/component/src/Toast/ExpandIcon.js
@@ -1,4 +1,3 @@
-import PropTypes from 'prop-types';
 import React from 'react';
 
 const ExpandIcon = ({ className }) => (
@@ -15,8 +14,4 @@ const ExpandIcon = ({ className }) => (
   </svg>
 );
 
-ExpandIcon.propTypes = {
-  className: PropTypes.string
-};
-
 export default ExpandIcon;
diff --git a/packages/component/src/Toast/NotificationIcon.js b/packages/component/src/Toast/NotificationIcon.js
index 6ebe6fe412..ad8136f055 100644
--- a/packages/component/src/Toast/NotificationIcon.js
+++ b/packages/component/src/Toast/NotificationIcon.js
@@ -1,6 +1,5 @@
 import { hooks } from 'botframework-webchat-api';
 import { isForbiddenPropertyName } from 'botframework-webchat-core';
-import PropTypes from 'prop-types';
 import React from 'react';
 
 import CheckMarkIcon from './CheckMarkIcon';
@@ -33,9 +32,4 @@ const NotificationIcon = ({ className, level }) => {
   );
 };
 
-NotificationIcon.propTypes = {
-  className: PropTypes.string,
-  level: PropTypes.oneOf(['error', 'info', 'success', 'warn']).isRequired
-};
-
 export default NotificationIcon;
diff --git a/packages/component/src/Transcript/ActivityRow.tsx b/packages/component/src/Transcript/ActivityRow.tsx
index 5395988b41..14a3da22f4 100644
--- a/packages/component/src/Transcript/ActivityRow.tsx
+++ b/packages/component/src/Transcript/ActivityRow.tsx
@@ -1,6 +1,5 @@
 import { hooks } from 'botframework-webchat-api';
 import classNames from 'classnames';
-import PropTypes from 'prop-types';
 import React, { forwardRef, memo, useCallback, useMemo, useRef } from 'react';
 import { useRefFrom } from 'use-ref-from';
 
@@ -25,7 +24,7 @@ import type { MouseEventHandler, PropsWithChildren } from 'react';
 
 const { useActivityKeysByRead, useGetHasAcknowledgedByActivityKey, useGetKeyByActivity } = hooks;
 
-type ActivityRowProps = PropsWithChildren<{ activity: WebChatActivity }>;
+type ActivityRowProps = PropsWithChildren<{ readonly activity: WebChatActivity }>;
 
 const ActivityRow = forwardRef<HTMLElement, ActivityRowProps>(({ activity, children }, ref) => {
   const [activeDescendantId] = useActiveDescendantId();
@@ -173,15 +172,4 @@ const ActivityRow = forwardRef<HTMLElement, ActivityRowProps>(({ activity, child
 
 ActivityRow.displayName = 'ActivityRow';
 
-ActivityRow.propTypes = {
-  // PropTypes cannot fully capture TypeScript type.
-  // @ts-ignore
-  activity: PropTypes.shape({
-    channelData: PropTypes.shape({
-      speak: PropTypes.bool,
-      'webchat:fallback-text': PropTypes.string
-    })
-  }).isRequired
-};
-
 export default memo(ActivityRow);
diff --git a/packages/component/src/Utils/TypeFocusSink/FocusBox.js b/packages/component/src/Utils/TypeFocusSink/FocusBox.js
index fcd12bc092..075f6905e2 100644
--- a/packages/component/src/Utils/TypeFocusSink/FocusBox.js
+++ b/packages/component/src/Utils/TypeFocusSink/FocusBox.js
@@ -1,6 +1,5 @@
 /* eslint no-undefined: "off" */
 
-import PropTypes from 'prop-types';
 import React, { forwardRef, useCallback, useMemo, useRef } from 'react';
 
 import Context from './Context';
@@ -72,15 +71,4 @@ const BaseFocusBox = (
 
 const FocusBox = forwardRef(BaseFocusBox);
 
-FocusBox.propTypes = BaseFocusBox.propTypes = {
-  children: PropTypes.any,
-  disabled: PropTypes.bool,
-  onKeyDownCapture: PropTypes.func,
-  sendFocusRef: PropTypes.shape({
-    current: PropTypes.shape({
-      focus: PropTypes.func
-    })
-  }).isRequired
-};
-
 export default FocusBox;
diff --git a/packages/component/src/providers/TranscriptFocus/TranscriptFocusComposer.tsx b/packages/component/src/providers/TranscriptFocus/TranscriptFocusComposer.tsx
index 3db4682857..cfd677bf15 100644
--- a/packages/component/src/providers/TranscriptFocus/TranscriptFocusComposer.tsx
+++ b/packages/component/src/providers/TranscriptFocus/TranscriptFocusComposer.tsx
@@ -1,6 +1,5 @@
 /* eslint-disable no-magic-numbers */
 import random from 'math-random';
-import PropTypes from 'prop-types';
 import React, { memo, useCallback, useMemo, type MutableRefObject, type ReactNode } from 'react';
 
 import usePrevious from '../../hooks/internal/usePrevious';
@@ -430,12 +429,4 @@ const TranscriptFocusComposer = ({ children, containerRef }: TranscriptFocusComp
 
 TranscriptFocusComposer.displayName = 'TranscriptFocusComposer';
 
-TranscriptFocusComposer.propTypes = {
-  // PropTypes is not fully compatible with TypeScript.
-  // @ts-ignore
-  containerRef: PropTypes.shape({
-    current: PropTypes.instanceOf(HTMLElement)
-  }).isRequired
-};
-
 export default memo(TranscriptFocusComposer);
diff --git a/packages/test/page-object/package.json b/packages/test/page-object/package.json
index 9d960ffb1f..dde63c65a9 100644
--- a/packages/test/page-object/package.json
+++ b/packages/test/page-object/package.json
@@ -46,7 +46,6 @@
     "event-target-shim": "6.0.2",
     "math-random": "2.0.1",
     "microsoft-cognitiveservices-speech-sdk": "1.50.0",
-    "prop-types": "15.8.1",
     "simple-update-in": "2.2.0"
   }
 }
diff --git a/packages/test/page-object/src/globals/testHelpers/activityGrouping/ActivityGroupingSurface.js b/packages/test/page-object/src/globals/testHelpers/activityGrouping/ActivityGroupingSurface.js
index beeba1d899..288dc2b14c 100644
--- a/packages/test/page-object/src/globals/testHelpers/activityGrouping/ActivityGroupingSurface.js
+++ b/packages/test/page-object/src/globals/testHelpers/activityGrouping/ActivityGroupingSurface.js
@@ -1,5 +1,3 @@
-import PropTypes from 'prop-types';
-
 import createDirectLineWithTranscript from '../createDirectLineWithTranscript';
 import ActivityGroupingContext from './ActivityGroupingContext';
 
@@ -248,8 +246,4 @@ const ActivityGroupingSurface = ({ children }) => {
   return <ActivityGroupingContext.Provider value={context}>{children}</ActivityGroupingContext.Provider>;
 };
 
-ActivityGroupingSurface.propTypes = {
-  children: PropTypes.any
-};
-
 export default ActivityGroupingSurface;
diff --git a/packages/test/page-object/src/globals/testHelpers/activityGrouping/Toggle.js b/packages/test/page-object/src/globals/testHelpers/activityGrouping/Toggle.js
index 9991a21b17..141f0e9c9a 100644
--- a/packages/test/page-object/src/globals/testHelpers/activityGrouping/Toggle.js
+++ b/packages/test/page-object/src/globals/testHelpers/activityGrouping/Toggle.js
@@ -1,5 +1,3 @@
-import PropTypes from 'prop-types';
-
 // Use React from window (UMD) instead of import.
 const { React: { useCallback, useMemo } = {} } = window;
 
@@ -15,12 +13,4 @@ const Toggle = ({ checked = false, children, disabled = false, onChange, type =
   );
 };
 
-Toggle.propTypes = {
-  checked: PropTypes.bool,
-  children: PropTypes.any,
-  disabled: PropTypes.bool,
-  onChange: PropTypes.func.isRequired,
-  type: PropTypes.string
-};
-
 export default Toggle;
diff --git a/packages/test/page-object/src/globals/testHelpers/createRenderWebChatWithHook.js b/packages/test/page-object/src/globals/testHelpers/createRenderWebChatWithHook.js
index 4d150cdf16..59dcae2d37 100644
--- a/packages/test/page-object/src/globals/testHelpers/createRenderWebChatWithHook.js
+++ b/packages/test/page-object/src/globals/testHelpers/createRenderWebChatWithHook.js
@@ -1,5 +1,3 @@
-import PropTypes from 'prop-types';
-
 import withResolvers from '../../utils/withResolvers';
 
 const RunHook = ({ fn, resolve }) => {
@@ -8,11 +6,6 @@ const RunHook = ({ fn, resolve }) => {
   return false;
 };
 
-RunHook.propTypes = {
-  fn: PropTypes.func,
-  resolve: PropTypes.func.isRequired
-};
-
 export default function createRenderWebChatWithHook(props, element) {
   const {
     WebChat: {