diff --git a/packages/docusaurus-plugin-content-docs/src/versions/__tests__/__fixtures__/site-js-sidebar/docs/hello.md b/packages/docusaurus-plugin-content-docs/src/versions/__tests__/__fixtures__/site-js-sidebar/docs/hello.md
new file mode 100644
index 000000000000..6e39f0eb8588
--- /dev/null
+++ b/packages/docusaurus-plugin-content-docs/src/versions/__tests__/__fixtures__/site-js-sidebar/docs/hello.md
@@ -0,0 +1 @@
+# Current documentation
diff --git a/packages/docusaurus-plugin-content-docs/src/versions/__tests__/__fixtures__/site-js-sidebar/versioned_docs/version-1.0.0/hello.md b/packages/docusaurus-plugin-content-docs/src/versions/__tests__/__fixtures__/site-js-sidebar/versioned_docs/version-1.0.0/hello.md
new file mode 100644
index 000000000000..362c2726d8c9
--- /dev/null
+++ b/packages/docusaurus-plugin-content-docs/src/versions/__tests__/__fixtures__/site-js-sidebar/versioned_docs/version-1.0.0/hello.md
@@ -0,0 +1 @@
+# Version 1 documentation
diff --git a/packages/docusaurus-plugin-content-docs/src/versions/__tests__/__fixtures__/site-js-sidebar/versioned_sidebars/version-1.0.0-sidebars.js b/packages/docusaurus-plugin-content-docs/src/versions/__tests__/__fixtures__/site-js-sidebar/versioned_sidebars/version-1.0.0-sidebars.js
new file mode 100644
index 000000000000..a2c5cc51a3b3
--- /dev/null
+++ b/packages/docusaurus-plugin-content-docs/src/versions/__tests__/__fixtures__/site-js-sidebar/versioned_sidebars/version-1.0.0-sidebars.js
@@ -0,0 +1,3 @@
+module.exports = {
+  docs: ['hello'],
+};
diff --git a/packages/docusaurus-plugin-content-docs/src/versions/__tests__/__fixtures__/site-js-sidebar/versions.json b/packages/docusaurus-plugin-content-docs/src/versions/__tests__/__fixtures__/site-js-sidebar/versions.json
new file mode 100644
index 000000000000..64de05e14b9e
--- /dev/null
+++ b/packages/docusaurus-plugin-content-docs/src/versions/__tests__/__fixtures__/site-js-sidebar/versions.json
@@ -0,0 +1 @@
+["1.0.0"]
diff --git a/packages/docusaurus-plugin-content-docs/src/versions/__tests__/files.test.ts b/packages/docusaurus-plugin-content-docs/src/versions/__tests__/files.test.ts
new file mode 100644
index 000000000000..08e352a95f34
--- /dev/null
+++ b/packages/docusaurus-plugin-content-docs/src/versions/__tests__/files.test.ts
@@ -0,0 +1,41 @@
+import {describe, expect, it} from 'vitest';
+import path from 'path';
+import {DEFAULT_PLUGIN_ID} from '@docusaurus/utils';
+import {getVersionSidebarsPath, resolveVersionSidebarsPath} from '../files';
+
+describe('getVersionSidebarsPath', () => {
+  it('returns the JSON versioned sidebar path', async () => {
+    expect(getVersionSidebarsPath('/site', DEFAULT_PLUGIN_ID, '1.0.0')).toBe(
+      path.join('/site', 'versioned_sidebars', 'version-1.0.0-sidebars.json'),
+    );
+  });
+  it('returns the JSON versioned sidebar path when using a version name', async () => {
+    expect(getVersionSidebarsPath('/site', DEFAULT_PLUGIN_ID, '2.0.0')).toBe(
+      path.join('/site', 'versioned_sidebars', 'version-2.0.0-sidebars.json'),
+    );
+  });
+  it('returns the JavaScript versioned sidebar path when it exists', async () => {
+    const siteDir = path.join(__dirname, 'fixtures');
+    const expectedPath = path.join(
+      siteDir,
+      'versioned_sidebars',
+      'version-1.0.0-sidebars.js',
+    );
+
+    await expect(
+      resolveVersionSidebarsPath(siteDir, DEFAULT_PLUGIN_ID, '1.0.0'),
+    ).resolves.toBe(expectedPath);
+  });
+  it('falls back to the JSON versioned sidebar path when no JavaScript file exists', async () => {
+    const siteDir = '/site';
+    const expectedPath = path.join(
+      siteDir,
+      'versioned_sidebars',
+      'version-1.0.0-sidebars.json',
+    );
+
+    await expect(
+      resolveVersionSidebarsPath(siteDir, DEFAULT_PLUGIN_ID, '1.0.0'),
+    ).resolves.toBe(expectedPath);
+  });
+});
diff --git a/packages/docusaurus-plugin-content-docs/src/versions/__tests__/fixtures/versioned_sidebars/version-1.0.0-sidebars.js b/packages/docusaurus-plugin-content-docs/src/versions/__tests__/fixtures/versioned_sidebars/version-1.0.0-sidebars.js
new file mode 100644
index 000000000000..ad43adfde190
--- /dev/null
+++ b/packages/docusaurus-plugin-content-docs/src/versions/__tests__/fixtures/versioned_sidebars/version-1.0.0-sidebars.js
@@ -0,0 +1,6 @@
+module.exports = {
+  docs: {
+    Test: ['foo/bar', 'foo/baz'],
+    Guides: ['hello'],
+  },
+};
diff --git a/packages/docusaurus-plugin-content-docs/src/versions/__tests__/loadVersion.test.ts b/packages/docusaurus-plugin-content-docs/src/versions/__tests__/loadVersion.test.ts
index 0beb0c6b8f3e..4bc1d591891d 100644
--- a/packages/docusaurus-plugin-content-docs/src/versions/__tests__/loadVersion.test.ts
+++ b/packages/docusaurus-plugin-content-docs/src/versions/__tests__/loadVersion.test.ts
@@ -59,6 +59,25 @@ async function siteFixture(fixture: string) {
 }
 
 describe('loadVersion', () => {
+  describe('site with JavaScript versioned sidebar', () => {
+    it('loads a versioned sidebar from a JavaScript file', async () => {
+      const {options, context, versions} = await siteFixture('site-js-sidebar');
+
+      const version = versions.find((v) => v.versionName === '1.0.0');
+      expect(version).toBeDefined();
+
+      const loadedVersion = await loadVersion({
+        context,
+        options,
+        versionMetadata: version!,
+        env: 'production',
+      });
+
+      expect(loadedVersion.sidebars).toEqual({
+        docs: [{type: 'doc', id: 'hello'}],
+      });
+    });
+  });
   describe('minimal site', () => {
     it('can load current version', async () => {
       const {options, context, versions} = await siteFixture('site-minimal');
diff --git a/packages/docusaurus-plugin-content-docs/src/versions/files.ts b/packages/docusaurus-plugin-content-docs/src/versions/files.ts
index 824c8092eef3..17c581c112e8 100644
--- a/packages/docusaurus-plugin-content-docs/src/versions/files.ts
+++ b/packages/docusaurus-plugin-content-docs/src/versions/files.ts
@@ -51,11 +51,31 @@ export function getVersionSidebarsPath(
   pluginId: string,
   versionName: string,
 ): string {
-  return path.join(
+  const sidebarsDir = path.join(
+    siteDir,
+    addPluginIdPrefix(VERSIONED_SIDEBARS_DIR, pluginId),
+  );
+
+  return path.join(sidebarsDir, `version-${versionName}-sidebars.json`);
+}
+
+/** Resolves a versioned sidebar, supporting both `.js` and `.json` files. */
+export async function resolveVersionSidebarsPath(
+  siteDir: string,
+  pluginId: string,
+  versionName: string,
+): Promise<string> {
+  const sidebarsDir = path.join(
     siteDir,
     addPluginIdPrefix(VERSIONED_SIDEBARS_DIR, pluginId),
-    `version-${versionName}-sidebars.json`,
   );
+
+  const baseName = `version-${versionName}-sidebars`;
+  const jsPath = path.join(sidebarsDir, `${baseName}.js`);
+
+  return (await fs.pathExists(jsPath))
+    ? jsPath
+    : getVersionSidebarsPath(siteDir, pluginId, versionName);
 }
 
 export function getDocsDirPathLocalized({
@@ -205,7 +225,11 @@ export async function getVersionMetadataPaths({
     : getVersionDocsDirPath(context.siteDir, options.id, versionName);
   const sidebarFilePath = isCurrent
     ? options.sidebarPath
-    : getVersionSidebarsPath(context.siteDir, options.id, versionName);
+    : await resolveVersionSidebarsPath(
+        context.siteDir,
+        options.id,
+        versionName,
+      );
 
   if (!(await fs.pathExists(contentPath))) {
     throw new Error(