diff --git a/components/SideBar.jsx b/components/SideBar.jsx
index 725e5e57..ffa79547 100644
--- a/components/SideBar.jsx
+++ b/components/SideBar.jsx
@@ -1,27 +1,42 @@
+import Select from '@node-core/ui-components/Common/Select';
 import SideBar from '@node-core/ui-components/Containers/Sidebar';
+import { major } from 'semver';
 import { sidebar } from '#theme/local/site';
+import { version } from '#theme/config';
+import versions from '../versions.json' with { type: 'json' };
 
 /** @param {string} url */
 const redirect = url => (window.location.href = url);
 
 const PrefetchLink = props => <a {...props} rel="prefetch" />;
 
+// The versioned API docs pass `sidebar` as an array of groups; the main site keys it by section.
+const isVersioned = Array.isArray(sidebar);
+
+// Versioned pages expose a version relative path, we prefix it so it matches the absolute sidebar links.
+const versionBase = isVersioned ? `/docs/api/v${version.major}.x` : '';
+
 const pathnameFor = path => {
-  const clean = path.replace(/\/index$/, '');
-  if (!clean) return '/';
-  return clean.startsWith('/') ? clean : `/${clean}`;
+  const clean = path.replace(/\/index$/, '').replace(/^\//, '');
+  return (clean ? `${versionBase}/${clean}` : versionBase) || '/';
 };
 
 const groupsFor = path => {
-  if (Array.isArray(sidebar)) return sidebar;
+  if (isVersioned) return sidebar;
 
   const segment = path.split('/').filter(Boolean)[0];
   return sidebar[segment] ?? [];
 };
 
-/**
- * Sidebar component for MDX documentation with page navigation.
- */
+const versionItems = versions.map(version => ({
+  value: `/docs/api/v${major(version)}.x`,
+  label: `v${major(version)}.x`,
+}));
+
+// Preselect the picker with the version this API build was generated for.
+const currentVersion = isVersioned ? versionBase : undefined;
+
+/** Docs sidebar, plus a webpack version picker on the versioned API docs. */
 export default ({ metadata }) => (
   <SideBar
     pathname={pathnameFor(metadata.path)}
@@ -29,5 +44,17 @@ export default ({ metadata }) => (
     onSelect={redirect}
     as={PrefetchLink}
     title="Navigation"
-  />
+  >
+    {isVersioned && (
+      <div>
+        <Select
+          label="webpack version"
+          values={versionItems}
+          value={currentVersion}
+          inline
+          onChange={redirect}
+        />
+      </div>
+    )}
+  </SideBar>
 );
diff --git a/scripts/markdown/governance.mjs b/scripts/markdown/governance.mjs
index 4e89d7b8..b47a6293 100644
--- a/scripts/markdown/governance.mjs
+++ b/scripts/markdown/governance.mjs
@@ -26,11 +26,14 @@ const FILE_MAP = {
   'AI_POLICY.md': { output: 'ai-policy', label: 'AI Policy' },
 };
 
+const pageLink = output =>
+  output === 'index' ? '/about/governance' : `/about/governance/${output}`;
+
 // Derived from FILE_MAP - stays in sync automatically if entries are added/removed.
 const LINK_REWRITE_MAP = Object.fromEntries(
   Object.entries(FILE_MAP).map(([source, { output }]) => [
     source,
-    `/about/governance/${output}`,
+    pageLink(output),
   ])
 );
 
@@ -77,7 +80,7 @@ const siteJson = {
     {
       groupName: 'Governance',
       items: fetched.map(({ output, label }) => ({
-        link: `/about/governance/${output}`,
+        link: pageLink(output),
         label,
       })),
     },