diff --git a/packages/react-components/react-toast/etc/react-toast.api.md b/packages/react-components/react-toast/etc/react-toast.api.md
index 04a9c293cea64..212a5f8126af5 100644
--- a/packages/react-components/react-toast/etc/react-toast.api.md
+++ b/packages/react-components/react-toast/etc/react-toast.api.md
@@ -19,6 +19,7 @@ export type ToastPosition = 'top-right' | 'top-center' | 'top-left' | 'bottom-ri
 export function useToastController(): {
     dispatchToast: (content: React_2.ReactNode, options?: Partial<ToastOptions> | undefined) => void;
     dismissToast: (toastId?: string | undefined) => void;
+    updateToast: (options: UpdateToastEventDetail) => void;
 };
 
 // (No @packageDocumentation comment for this package)
diff --git a/packages/react-components/react-toast/src/components/Toast.tsx b/packages/react-components/react-toast/src/components/Toast.tsx
index 19c538935f37a..77f89beeeb851 100644
--- a/packages/react-components/react-toast/src/components/Toast.tsx
+++ b/packages/react-components/react-toast/src/components/Toast.tsx
@@ -77,7 +77,7 @@ const useStyles = makeStyles({
 
 export const Toast: React.FC<ToastProps & { visible: boolean }> = props => {
   const styles = useStyles();
-  const { visible, children, close, remove, ...toastOptions } = props;
+  const { visible, children, close, remove, updateId, ...toastOptions } = props;
   const { timeout } = toastOptions;
   const { play, running, toastRef } = useToast<HTMLDivElement>({ ...toastOptions, content: children });
 
@@ -99,7 +99,7 @@ export const Toast: React.FC<ToastProps & { visible: boolean }> = props => {
     <Transition in={visible} unmountOnExit mountOnEnter timeout={500} onExited={remove} nodeRef={toastRef}>
       <div ref={toastRef} className={mergeClasses(styles.toast, visible && styles.slide, !visible && styles.fadeOut)}>
         {children}
-        <Timer onTimeout={close} timeout={timeout ?? -1} running={running} />
+        <Timer key={updateId} onTimeout={close} timeout={timeout ?? -1} running={running} />
       </div>
     </Transition>
   );
diff --git a/packages/react-components/react-toast/src/state/constants.ts b/packages/react-components/react-toast/src/state/constants.ts
index 9ca243fc8dcc6..003bad5391867 100644
--- a/packages/react-components/react-toast/src/state/constants.ts
+++ b/packages/react-components/react-toast/src/state/constants.ts
@@ -1,4 +1,5 @@
 export const EVENTS = {
   show: 'fui-toast-show',
   dismiss: 'fui-toast-dismiss',
+  update: 'fui-toast-update',
 } as const;
diff --git a/packages/react-components/react-toast/src/state/types.ts b/packages/react-components/react-toast/src/state/types.ts
index a9161b84757cb..86c419864ecf4 100644
--- a/packages/react-components/react-toast/src/state/types.ts
+++ b/packages/react-components/react-toast/src/state/types.ts
@@ -22,12 +22,17 @@ export interface ToasterOptions
 export interface Toast extends ToastOptions {
   close: () => void;
   remove: () => void;
+  updateId: number;
 }
 
 export interface ShowToastEventDetail extends Partial<ToastOptions> {
   toastId: ToastId;
 }
 
+export interface UpdateToastEventDetail extends Partial<ToastOptions> {
+  toastId: ToastId;
+}
+
 export interface DismissToastEventDetail {
   toastId: ToastId | undefined;
 }
@@ -37,4 +42,5 @@ type EventListener<TDetail> = (e: CustomEvent<TDetail>) => void;
 export type ToastListenerMap = {
   [EVENTS.show]: EventListener<ShowToastEventDetail>;
   [EVENTS.dismiss]: EventListener<DismissToastEventDetail>;
+  [EVENTS.update]: EventListener<UpdateToastEventDetail>;
 };
diff --git a/packages/react-components/react-toast/src/state/useToastController.ts b/packages/react-components/react-toast/src/state/useToastController.ts
index fbd64588edace..5eb4c33ae377c 100644
--- a/packages/react-components/react-toast/src/state/useToastController.ts
+++ b/packages/react-components/react-toast/src/state/useToastController.ts
@@ -1,31 +1,36 @@
-import { useFluent_unstable as useFluent } from '@fluentui/react-shared-contexts';
-import { dispatchToast as dispatchToastVanilla, dismissToast as dismissToastVanilla } from './vanilla';
 import * as React from 'react';
-import { ToastId, ToastOptions } from './types';
+import { useFluent_unstable as useFluent } from '@fluentui/react-shared-contexts';
+import {
+  dispatchToast as dispatchToastVanilla,
+  dismissToast as dismissToastVanilla,
+  updateToast as updateToastVanilla,
+} from './vanilla';
+import { ToastId, ToastOptions, UpdateToastEventDetail } from './types';
+
+const noop = () => undefined;
 
 export function useToastController() {
   const { targetDocument } = useFluent();
 
-  const dispatchToast = React.useCallback(
-    (content: React.ReactNode, options?: Partial<ToastOptions>) => {
-      if (targetDocument) {
-        dispatchToastVanilla(content, options, targetDocument);
-      }
-    },
-    [targetDocument],
-  );
+  return React.useMemo(() => {
+    if (!targetDocument) {
+      return {
+        dispatchToast: noop,
+        dismissToast: noop,
+        updateToast: noop,
+      };
+    }
 
-  const dismissToast = React.useCallback(
-    (toastId?: ToastId) => {
-      if (targetDocument) {
+    return {
+      dispatchToast: (content: React.ReactNode, options?: Partial<ToastOptions>) => {
+        dispatchToastVanilla(content, options, targetDocument);
+      },
+      dismissToast: (toastId?: Partial<ToastId>) => {
         dismissToastVanilla(toastId, targetDocument);
-      }
-    },
-    [targetDocument],
-  );
-
-  return {
-    dispatchToast,
-    dismissToast,
-  };
+      },
+      updateToast: (options: UpdateToastEventDetail) => {
+        updateToastVanilla(options, targetDocument);
+      },
+    };
+  }, [targetDocument]);
 }
diff --git a/packages/react-components/react-toast/src/state/vanilla/index.ts b/packages/react-components/react-toast/src/state/vanilla/index.ts
index 78e6c1e54e5b2..c7a2e61893079 100644
--- a/packages/react-components/react-toast/src/state/vanilla/index.ts
+++ b/packages/react-components/react-toast/src/state/vanilla/index.ts
@@ -1,5 +1,6 @@
 export * from './dispatchToast';
 export * from './dismissToast';
+export * from './updateToast';
 export * from './toast';
 export * from './toaster';
 export * from './getPositionStyles';
diff --git a/packages/react-components/react-toast/src/state/vanilla/toaster.ts b/packages/react-components/react-toast/src/state/vanilla/toaster.ts
index 38d327e638b9a..24314a84e76f1 100644
--- a/packages/react-components/react-toast/src/state/vanilla/toaster.ts
+++ b/packages/react-components/react-toast/src/state/vanilla/toaster.ts
@@ -1,4 +1,4 @@
-import { Toast, ToasterOptions, ToastId, ToastOptions, ToastListenerMap } from '../types';
+import { Toast, ToasterOptions, ToastId, ToastOptions, ToastListenerMap, UpdateToastEventDetail } from '../types';
 import { EVENTS } from '../constants';
 
 function assignDefined<T extends object>(a: Partial<T>, b: Partial<T>) {
@@ -49,6 +49,7 @@ export class Toaster {
     assignDefined(this.toasterOptions, options);
 
     const buildToast: ToastListenerMap[typeof EVENTS.show] = e => this._buildToast(e.detail);
+    const updateToast: ToastListenerMap[typeof EVENTS.update] = e => this._updateToast(e.detail);
     const dismissToast: ToastListenerMap[typeof EVENTS.dismiss] = e => {
       const { toastId } = e.detail;
       if (toastId) {
@@ -58,11 +59,9 @@ export class Toaster {
       }
     };
 
-    this.listeners.set(EVENTS.show, buildToast);
-    this.listeners.set(EVENTS.dismiss, dismissToast);
-
     this._addEventListener(EVENTS.show, buildToast);
     this._addEventListener(EVENTS.dismiss, dismissToast);
+    this._addEventListener(EVENTS.update, updateToast);
   }
 
   public isToastVisible = (toastId: ToastId) => {
@@ -74,6 +73,7 @@ export class Toaster {
       return;
     }
 
+    this.listeners.set(eventType, callback);
     const targetDocument = this.toasterElement?.ownerDocument;
     targetDocument.addEventListener(eventType, callback as () => void);
   }
@@ -90,6 +90,18 @@ export class Toaster {
     targetDocument.removeEventListener(eventType, callback as () => void);
   }
 
+  private _updateToast(toastOptions: UpdateToastEventDetail) {
+    const { toastId } = toastOptions;
+    const toastToUpdate = this.toasts.get(toastId);
+    if (!toastToUpdate) {
+      return;
+    }
+
+    Object.assign(toastToUpdate, toastOptions);
+    toastToUpdate.updateId++;
+    this.onUpdate();
+  }
+
   private _dismissToast(toastId: ToastId) {
     this.visibleToasts.delete(toastId);
     this.onUpdate();
@@ -123,6 +135,7 @@ export class Toaster {
       remove,
       toastId,
       content,
+      updateId: 0,
     };
 
     assignDefined<Toast>(toast, toastOptions);
diff --git a/packages/react-components/react-toast/src/state/vanilla/updateToast.ts b/packages/react-components/react-toast/src/state/vanilla/updateToast.ts
new file mode 100644
index 0000000000000..e708df31823ef
--- /dev/null
+++ b/packages/react-components/react-toast/src/state/vanilla/updateToast.ts
@@ -0,0 +1,12 @@
+import { UpdateToastEventDetail } from '../types';
+import { EVENTS } from '../constants';
+
+export function updateToast(options: UpdateToastEventDetail, targetDocument: Document) {
+  const event = new CustomEvent<UpdateToastEventDetail>(EVENTS.update, {
+    bubbles: false,
+    cancelable: false,
+    detail: options,
+  });
+
+  targetDocument.dispatchEvent(event);
+}
diff --git a/packages/react-components/react-toast/stories/Toast/UpdateToast.stories.tsx b/packages/react-components/react-toast/stories/Toast/UpdateToast.stories.tsx
new file mode 100644
index 0000000000000..b20ab45a4ec5e
--- /dev/null
+++ b/packages/react-components/react-toast/stories/Toast/UpdateToast.stories.tsx
@@ -0,0 +1,16 @@
+import * as React from 'react';
+import { Toaster, useToastController, ToastId } from '@fluentui/react-toast';
+
+export const UpdateToast = () => {
+  const { dispatchToast, updateToast } = useToastController();
+  const notify = (id: ToastId) => dispatchToast('This toast never closes', { toastId: id, timeout: -1 });
+  const update = (id: ToastId) => updateToast({ content: 'This toast will close soon', toastId: id, timeout: 1000 });
+
+  return (
+    <>
+      <Toaster />
+      <button onClick={() => notify('EXAMPLE_ID')}>Make toast</button>
+      <button onClick={() => update('EXAMPLE_ID')}>Update toast</button>
+    </>
+  );
+};
diff --git a/packages/react-components/react-toast/stories/Toast/index.stories.tsx b/packages/react-components/react-toast/stories/Toast/index.stories.tsx
index 96353ca5bdbd8..67513a4be27e2 100644
--- a/packages/react-components/react-toast/stories/Toast/index.stories.tsx
+++ b/packages/react-components/react-toast/stories/Toast/index.stories.tsx
@@ -6,6 +6,7 @@ export { DismissToast } from './DismissToast.stories';
 export { DismissAll } from './DismissAll.stories';
 export { PauseOnWindowBlur } from './PauseOnWindowBlur.stories';
 export { PauseOnHover } from './PauseOnHover.stories';
+export { UpdateToast } from './UpdateToast.stories';
 
 export default {
   title: 'Preview Components/Toast',