diff --git a/packages/docusaurus-theme-classic/src/__tests__/inlineScripts.test.ts b/packages/docusaurus-theme-classic/src/__tests__/inlineScripts.test.ts
index 2690e0b09c89..5763ea40874b 100644
--- a/packages/docusaurus-theme-classic/src/__tests__/inlineScripts.test.ts
+++ b/packages/docusaurus-theme-classic/src/__tests__/inlineScripts.test.ts
@@ -6,7 +6,10 @@
  */
 
 import {describe, expect, it} from 'vitest';
-import {getThemeInlineScript} from '../inlineScripts';
+import {
+  getThemeInlineScript,
+  getAnnouncementBarInlineScript,
+} from '../inlineScripts';
 
 describe('inlineScripts', () => {
   it('inline javascript for default options', () => {
@@ -40,4 +43,125 @@ describe('inlineScripts', () => {
       }),
     ).toMatchSnapshot();
   });
+
+  describe('getAnnouncementBarInlineScript', () => {
+    it('generates inline script with default announcement id and namespace', () => {
+      const script = getAnnouncementBarInlineScript({
+        siteStorage: {
+          type: 'localStorage',
+          namespace: '',
+        },
+      });
+      expect(script).toContain(
+        'localStorage.getItem(\'docusaurus.announcement.id\') !== "announcement-bar"',
+      );
+      expect(script).toContain(
+        "localStorage.getItem('docusaurus.announcement.dismiss') === 'true'",
+      );
+      expect(script).toContain(
+        "document.documentElement.setAttribute('data-announcement-bar-initially-dismissed', isDismissed())",
+      );
+    });
+
+    it('generates inline script with custom announcement id and custom namespace', () => {
+      const script = getAnnouncementBarInlineScript({
+        siteStorage: {
+          type: 'localStorage',
+          namespace: '.custom-namespace',
+        },
+        announcementBar: {
+          id: 'announcement-v2',
+        },
+      });
+      expect(script).toContain(
+        'localStorage.getItem(\'docusaurus.announcement.id.custom-namespace\') !== "announcement-v2"',
+      );
+      expect(script).toContain(
+        "localStorage.getItem('docusaurus.announcement.dismiss.custom-namespace') === 'true'",
+      );
+    });
+
+    it('evaluates to false when a new announcement id differs from dismissed one', () => {
+      const script = getAnnouncementBarInlineScript({
+        siteStorage: {
+          type: 'localStorage',
+          namespace: '',
+        },
+        announcementBar: {
+          id: 'announcement-v2',
+        },
+      });
+
+      const store = new Map<string, string>();
+      const mockLocalStorage = {
+        getItem: (key: string) => store.get(key) ?? null,
+        setItem: (key: string, value: string) => store.set(key, value),
+      };
+      let attributeValue = '';
+      const mockDocument = {
+        documentElement: {
+          setAttribute: (_name: string, value: string | boolean) => {
+            attributeValue = String(value);
+          },
+        },
+      };
+
+      const fn = new Function('localStorage', 'document', script);
+
+      // Simulate a user who dismissed announcement-v1
+      mockLocalStorage.setItem('docusaurus.announcement.id', 'announcement-v1');
+      mockLocalStorage.setItem('docusaurus.announcement.dismiss', 'true');
+
+      fn(mockLocalStorage, mockDocument);
+      expect(attributeValue).toBe('false');
+
+      // Simulate missing stored announcement ID while dismissal flag is true
+      store.delete('docusaurus.announcement.id');
+      fn(mockLocalStorage, mockDocument);
+      expect(attributeValue).toBe('false');
+
+      // Simulate when user has dismissed current announcement-v2
+      mockLocalStorage.setItem('docusaurus.announcement.id', 'announcement-v2');
+
+      fn(mockLocalStorage, mockDocument);
+      expect(attributeValue).toBe('true');
+    });
+
+    it('escapes closing script tags in announcement id', () => {
+      const script = getAnnouncementBarInlineScript({
+        siteStorage: {
+          type: 'localStorage',
+          namespace: '',
+        },
+        announcementBar: {
+          id: 'x</script><script>alert(1)</script>',
+        },
+      });
+      expect(script).not.toContain('</script>');
+      expect(script).toContain('\\u003c/script>');
+
+      const store = new Map<string, string>();
+      const mockLocalStorage = {
+        getItem: (key: string) => store.get(key) ?? null,
+        setItem: (key: string, value: string) => store.set(key, value),
+      };
+      let attributeValue = '';
+      const mockDocument = {
+        documentElement: {
+          setAttribute: (_name: string, value: string | boolean) => {
+            attributeValue = String(value);
+          },
+        },
+      };
+
+      const fn = new Function('localStorage', 'document', script);
+      mockLocalStorage.setItem(
+        'docusaurus.announcement.id',
+        'x</script><script>alert(1)</script>',
+      );
+      mockLocalStorage.setItem('docusaurus.announcement.dismiss', 'true');
+      fn(mockLocalStorage, mockDocument);
+      expect(attributeValue).toBe('true');
+    });
+  });
 });
diff --git a/packages/docusaurus-theme-classic/src/index.ts b/packages/docusaurus-theme-classic/src/index.ts
index 8c5a236835a3..b57e3bf69eb1 100644
--- a/packages/docusaurus-theme-classic/src/index.ts
+++ b/packages/docusaurus-theme-classic/src/index.ts
@@ -134,7 +134,7 @@ export default function themeClassic(
             innerHTML: `
 ${getThemeInlineScript({colorMode, siteStorage})}
 ${DataAttributeQueryStringInlineJavaScript}
-${announcementBar ? getAnnouncementBarInlineScript({siteStorage}) : ''}
+${announcementBar ? getAnnouncementBarInlineScript({siteStorage, announcementBar}) : ''}
             `,
           },
         ],
diff --git a/packages/docusaurus-theme-classic/src/inlineScripts.ts b/packages/docusaurus-theme-classic/src/inlineScripts.ts
index fe49094a52c4..fbc502735f19 100644
--- a/packages/docusaurus-theme-classic/src/inlineScripts.ts
+++ b/packages/docusaurus-theme-classic/src/inlineScripts.ts
@@ -76,21 +76,31 @@ export const DataAttributeQueryStringInlineJavaScript = `
 // the announcement bar asap (before React hydration)
 export function getAnnouncementBarInlineScript({
   siteStorage,
+  announcementBar,
 }: {
   siteStorage: SiteStorage;
+  announcementBar?: {id?: string};
 }): string {
   // Duplicated constant. Unfortunately we can't import it from theme-common, as
   // we need to support older nodejs versions without ESM support
   // TODO: import from theme-common once we support Node.js with ESM support
   // + move all those announcementBar stuff there too
   const AnnouncementBarDismissStorageKey = `docusaurus.announcement.dismiss${siteStorage.namespace}`;
+  const AnnouncementBarIdStorageKey = `docusaurus.announcement.id${siteStorage.namespace}`;
   const AnnouncementBarDismissDataAttribute =
     'data-announcement-bar-initially-dismissed';
+  const id = announcementBar?.id ?? 'announcement-bar';
+  // Escape '<' to prevent breaking out of inline <script> tags
+  // See https://redux.js.org/recipes/server-rendering/#security-considerations
+  const serializedId = JSON.stringify(id).replace(/</g, '\\u003c');
 
   /* language=js */
   return `(function() {
   function isDismissed() {
     try {
+      if (localStorage.getItem('${AnnouncementBarIdStorageKey}') !== ${serializedId}) {
+        return false;
+      }
       return localStorage.getItem('${AnnouncementBarDismissStorageKey}') === 'true';
     } catch (err) {}
     return false;
diff --git a/packages/docusaurus-theme-common/src/contexts/announcementBar.tsx b/packages/docusaurus-theme-common/src/contexts/announcementBar.tsx
index 71546d20d2b4..e0570b7531a9 100644
--- a/packages/docusaurus-theme-common/src/contexts/announcementBar.tsx
+++ b/packages/docusaurus-theme-common/src/contexts/announcementBar.tsx
@@ -25,7 +25,8 @@ const AnnouncementBarDismissStorage = createStorageSlot(
 );
 const IdStorage = createStorageSlot('docusaurus.announcement.id');
 
-const isDismissedInStorage = () =>
+const isDismissedInStorage = (id?: string) =>
+  (!id || IdStorage.get() === id) &&
   AnnouncementBarDismissStorage.get() === 'true';
 const setDismissedInStorage = (bool: boolean) =>
   AnnouncementBarDismissStorage.set(String(bool));
@@ -48,19 +49,22 @@ function useContextValue(): ContextValue {
   const [isClosed, setClosed] = useState(() =>
     isBrowser
       ? // On client navigation: init with local storage value
-        isDismissedInStorage()
+        isDismissedInStorage(announcementBar?.id)
       : // On server/hydration: always visible to prevent layout shifts (will be hidden with css if needed)
         false,
   );
   // Update state after hydration
   useEffect(() => {
-    setClosed(isDismissedInStorage());
-  }, []);
+    setClosed(isDismissedInStorage(announcementBar?.id));
+  }, [announcementBar?.id]);
 
   const handleClose = useCallback(() => {
+    if (announcementBar) {
+      IdStorage.set(announcementBar.id);
+    }
     setDismissedInStorage(true);
     setClosed(true);
-  }, []);
+  }, [announcementBar]);
 
   useEffect(() => {
     if (!announcementBar) {
@@ -77,7 +81,7 @@ function useContextValue(): ContextValue {
       setDismissedInStorage(false);
     }
 
-    if (isNewAnnouncement || !isDismissedInStorage()) {
+    if (isNewAnnouncement || !isDismissedInStorage(id)) {
       setClosed(false);
     }
   }, [announcementBar]);