diff --git a/src/elements/content-uploader/ContentUploader.tsx b/src/elements/content-uploader/ContentUploader.tsx
index d9f3856da3..928bd3ae12 100644
--- a/src/elements/content-uploader/ContentUploader.tsx
+++ b/src/elements/content-uploader/ContentUploader.tsx
@@ -112,6 +112,8 @@ export interface ContentUploaderProps {
     uploadHost: string;
     useUploadsManager?: boolean;
     enableModernizedUploads?: boolean;
+    isExpanded?: boolean;
+    onToggle?: (isExpanded: boolean) => void;
 }
 
 type State = {
@@ -655,7 +657,7 @@ class ContentUploader extends Component<ContentUploaderProps, State> {
      */
     addToQueue = (newItems: UploadItem[], itemUpdateCallback: Function) => {
         const { fileLimit, useUploadsManager } = this.props;
-        const { isUploadsManagerExpanded } = this.state;
+        const isUploadsManagerExpanded = this.getIsExpanded();
 
         let updatedItems = [];
         const prevItemsNum = this.itemsRef.current.length;
@@ -965,8 +967,35 @@ class ContentUploader extends Component<ContentUploaderProps, State> {
         });
     };
 
+    /**
+     * Whether the component is in controlled-expand mode.
+     *
+     * @return {boolean}
+     */
+    isExpandControlled = (): boolean => this.props.isExpanded !== undefined;
+
+    /**
+     * Returns the resolved expanded state. When `isExpanded` prop is provided
+     * the component is in controlled mode and the prop wins; otherwise the
+     * internal state is used (uncontrolled mode).
+     *
+     * @return {boolean}
+     */
+    getIsExpanded = (): boolean => {
+        if (this.isExpandControlled()) {
+            return this.props.isExpanded;
+        }
+
+        return this.state.isUploadsManagerExpanded;
+    };
+
     resetUploadManagerExpandState = () => {
         this.isAutoExpanded = false;
+        // In controlled mode the consumer owns the expanded state. Auto-collapse
+        // (post-completion timeout, cancel-all) must not mutate that preference.
+        if (this.isExpandControlled()) {
+            return;
+        }
         this.setState({
             isUploadsManagerExpanded: false,
         });
@@ -1297,6 +1326,12 @@ class ContentUploader extends Component<ContentUploaderProps, State> {
 
         clearTimeout(this.resetItemsTimeout);
 
+        // In controlled mode the consumer owns the expanded state. Auto-expand
+        // (file-count threshold) must not mutate that preference.
+        if (this.isExpandControlled()) {
+            return;
+        }
+
         this.setState({ isUploadsManagerExpanded: true });
     };
 
@@ -1337,13 +1372,17 @@ class ContentUploader extends Component<ContentUploaderProps, State> {
      * @return {void}
      */
     toggleUploadsManager = (): void => {
-        const { isUploadsManagerExpanded } = this.state;
+        const { onToggle } = this.props;
+        const isExpanded = this.getIsExpanded();
+        const nextExpanded = !isExpanded;
 
-        if (isUploadsManagerExpanded) {
+        if (isExpanded) {
             this.minimizeUploadsManager();
-        } else {
+        } else if (!this.isExpandControlled()) {
             this.expandUploadsManager();
         }
+
+        onToggle?.(nextExpanded);
     };
 
     /**
@@ -1397,7 +1436,8 @@ class ContentUploader extends Component<ContentUploaderProps, State> {
      */
     resetUploadsManagerItemsWhenUploadsComplete = (): void => {
         const { onCancel, useUploadsManager } = this.props;
-        const { isUploadsManagerExpanded, view } = this.state;
+        const { view } = this.state;
+        const isUploadsManagerExpanded = this.getIsExpanded();
 
         // Do not reset items when upload manger is expanded or there're uploads in progress
         if (
@@ -1459,7 +1499,8 @@ class ContentUploader extends Component<ContentUploaderProps, State> {
             theme,
             useUploadsManager,
         }: ContentUploaderProps = this.props;
-        const { view, items, errorCode, isCancelAllModalOpen, isUploadsManagerExpanded }: State = this.state;
+        const { view, items, errorCode, isCancelAllModalOpen }: State = this.state;
+        const isUploadsManagerExpanded = this.getIsExpanded();
         const isEmpty = items.length === 0;
         const isVisible = !isEmpty || !!isDraggingItemsToUploadsManager;
 
diff --git a/src/elements/content-uploader/__tests__/ContentUploader.test.js b/src/elements/content-uploader/__tests__/ContentUploader.test.js
index 0697862b00..96be39a4ae 100644
--- a/src/elements/content-uploader/__tests__/ContentUploader.test.js
+++ b/src/elements/content-uploader/__tests__/ContentUploader.test.js
@@ -680,6 +680,123 @@ describe('elements/content-uploader/ContentUploader', () => {
         });
     });
 
+    describe('controlled isExpanded / onToggle', () => {
+        test('uses isExpanded prop value when in controlled mode', () => {
+            const wrapper = getWrapper({ enableModernizedUploads: true, isExpanded: true, onToggle: jest.fn() });
+            expect(wrapper.find(UploadsManagerBP).prop('isExpanded')).toBe(true);
+
+            wrapper.setProps({ isExpanded: false });
+            expect(wrapper.find(UploadsManagerBP).prop('isExpanded')).toBe(false);
+        });
+
+        test('falls back to internal state when isExpanded prop is not provided', () => {
+            const wrapper = getWrapper({ enableModernizedUploads: true });
+            expect(wrapper.find(UploadsManagerBP).prop('isExpanded')).toBe(false);
+
+            wrapper.setState({ isUploadsManagerExpanded: true });
+            expect(wrapper.find(UploadsManagerBP).prop('isExpanded')).toBe(true);
+        });
+
+        test('toggleUploadsManager calls onToggle with next value in controlled mode and does not mutate internal state', () => {
+            const onToggle = jest.fn();
+            const wrapper = getWrapper({
+                enableModernizedUploads: true,
+                useUploadsManager: true,
+                isExpanded: false,
+                onToggle,
+            });
+
+            wrapper.instance().toggleUploadsManager();
+
+            expect(onToggle).toHaveBeenCalledTimes(1);
+            expect(onToggle).toHaveBeenCalledWith(true);
+            expect(wrapper.state().isUploadsManagerExpanded).toBe(false);
+        });
+
+        test('toggleUploadsManager flips internal state in uncontrolled mode and fires onToggle', () => {
+            const onToggle = jest.fn();
+            const wrapper = getWrapper({ useUploadsManager: true, onToggle });
+
+            wrapper.instance().toggleUploadsManager();
+
+            expect(wrapper.state().isUploadsManagerExpanded).toBe(true);
+            expect(onToggle).toHaveBeenCalledTimes(1);
+            expect(onToggle).toHaveBeenCalledWith(true);
+        });
+
+        test('toggleUploadsManager does not require onToggle in uncontrolled mode', () => {
+            const wrapper = getWrapper({ useUploadsManager: true });
+
+            expect(() => wrapper.instance().toggleUploadsManager()).not.toThrow();
+            expect(wrapper.state().isUploadsManagerExpanded).toBe(true);
+        });
+
+        test('auto-expand on file-count threshold does not mutate state in controlled mode', () => {
+            const onToggle = jest.fn();
+            const wrapper = getWrapper({
+                useUploadsManager: true,
+                isExpanded: false,
+                onToggle,
+            });
+            const instance = wrapper.instance();
+            const mockAPI = { upload: () => {} };
+            instance.createAPIFactory = jest.fn().mockReturnValue({
+                getPlainUploadAPI: () => mockAPI,
+                getChunkedUploadAPI: () => mockAPI,
+            });
+
+            const files = createMockFiles(EXPAND_UPLOADS_MANAGER_ITEMS_NUM_THRESHOLD + 1);
+            wrapper.setProps({ files });
+
+            expect(wrapper.state().isUploadsManagerExpanded).toBe(false);
+            // Auto-expand must not leak into the persisted preference via onToggle.
+            expect(onToggle).not.toHaveBeenCalled();
+        });
+
+        test('controlled-mode collapse runs minimizeUploadsManager side effects (onMinimize, cleanup timer, isAutoExpanded reset)', () => {
+            jest.useFakeTimers();
+            const onToggle = jest.fn();
+            const onMinimize = jest.fn();
+            const wrapper = getWrapper({
+                enableModernizedUploads: true,
+                useUploadsManager: true,
+                isExpanded: true,
+                onToggle,
+                onMinimize,
+            });
+            const instance = wrapper.instance();
+            instance.isAutoExpanded = true;
+            instance.checkClearUploadItems = jest.fn();
+
+            instance.toggleUploadsManager();
+
+            expect(onToggle).toHaveBeenCalledWith(false);
+            expect(onMinimize).toHaveBeenCalledTimes(1);
+            expect(instance.isAutoExpanded).toBe(false);
+            expect(instance.checkClearUploadItems).toHaveBeenCalledTimes(1);
+            // Internal state still owned by consumer — untouched.
+            expect(wrapper.state().isUploadsManagerExpanded).toBe(false);
+            jest.useRealTimers();
+        });
+
+        test('auto-collapse via resetUploadManagerExpandState is a no-op in controlled mode', () => {
+            const onToggle = jest.fn();
+            const wrapper = getWrapper({
+                useUploadsManager: true,
+                isExpanded: true,
+                onToggle,
+            });
+            const instance = wrapper.instance();
+            instance.isAutoExpanded = true;
+
+            instance.resetUploadManagerExpandState();
+
+            expect(instance.isAutoExpanded).toBe(false);
+            expect(wrapper.state().isUploadsManagerExpanded).toBe(false); // initial default
+            expect(onToggle).not.toHaveBeenCalled();
+        });
+    });
+
     describe('componentDidMount()', () => {
         test('adds files to upload queue if isPrepopulateFilesEnabled is true and files are provided', () => {
             const files = createMockFiles(3);