diff --git a/packages/docusaurus/src/commands/serve/__tests__/requestHandler.test.ts b/packages/docusaurus/src/commands/serve/__tests__/requestHandler.test.ts
index 0c8b5056066a..fba669d755d6 100644
--- a/packages/docusaurus/src/commands/serve/__tests__/requestHandler.test.ts
+++ b/packages/docusaurus/src/commands/serve/__tests__/requestHandler.test.ts
@@ -155,9 +155,9 @@ describe('createServeRequestHandler', () => {
         /missing                    404 404.html
         /missing/                   404 404.html
         /missing.html               301 /missing → 404 404.html
-        /redirect-folder.html       301 /redirect-folder → 404 404.html
+        /redirect-folder.html       200 redirect-folder.html/index.html
         /redirect-folder.html/      200 redirect-folder.html/index.html
-        /redirect-file.html         301 /redirect-file → 404 404.html
+        /redirect-file.html         200 redirect-file.html.html
         /redirect-file.html/        200 redirect-file.html.html
         /file?query=1               200 file.html
         /file/?query=1              200 file.html
@@ -219,9 +219,9 @@ describe('createServeRequestHandler', () => {
         /missing                    301 /missing/ → 404 404.html
         /missing/                   404 404.html
         /missing.html               301 /missing → 301 /missing/ → 404 404.html
-        /redirect-folder.html       301 /redirect-folder → 301 /redirect-folder/ → 404 404.html
+        /redirect-folder.html       301 /redirect-folder.html/ → 200 redirect-folder.html/index.html
         /redirect-folder.html/      200 redirect-folder.html/index.html
-        /redirect-file.html         301 /redirect-file → 301 /redirect-file/ → 404 404.html
+        /redirect-file.html         301 /redirect-file.html/ → 200 redirect-file.html.html
         /redirect-file.html/        200 redirect-file.html.html
         /file?query=1               301 /file/?query=1 → 200 file.html
         /file/?query=1              200 file.html
@@ -283,10 +283,10 @@ describe('createServeRequestHandler', () => {
         /missing                    404 404.html
         /missing/                   301 /missing → 404 404.html
         /missing.html               301 /missing → 404 404.html
-        /redirect-folder.html       301 /redirect-folder → 404 404.html
-        /redirect-folder.html/      301 /redirect-folder.html → 301 /redirect-folder → 404 404.html
-        /redirect-file.html         301 /redirect-file → 404 404.html
-        /redirect-file.html/        301 /redirect-file.html → 301 /redirect-file → 404 404.html
+        /redirect-folder.html       200 redirect-folder.html/index.html
+        /redirect-folder.html/      301 /redirect-folder.html → 200 redirect-folder.html/index.html
+        /redirect-file.html         200 redirect-file.html.html
+        /redirect-file.html/        301 /redirect-file.html → 200 redirect-file.html.html
         /file?query=1               200 file.html
         /file/?query=1              301 /file?query=1 → 200 file.html
         /file.html?query=1          200 file.html
@@ -349,9 +349,9 @@ describe('createServeRequestHandler', () => {
         /base/missing                    404 404.html
         /base/missing/                   404 404.html
         /base/missing.html               301 /base/missing → 404 404.html
-        /base/redirect-folder.html       301 /base/redirect-folder → 404 404.html
+        /base/redirect-folder.html       200 redirect-folder.html/index.html
         /base/redirect-folder.html/      200 redirect-folder.html/index.html
-        /base/redirect-file.html         301 /base/redirect-file → 404 404.html
+        /base/redirect-file.html         200 redirect-file.html.html
         /base/redirect-file.html/        200 redirect-file.html.html
         /base/file?query=1               200 file.html
         /base/file/?query=1              200 file.html
@@ -413,9 +413,9 @@ describe('createServeRequestHandler', () => {
         /base/missing                    301 /base/missing/ → 404 404.html
         /base/missing/                   404 404.html
         /base/missing.html               301 /base/missing → 301 /base/missing/ → 404 404.html
-        /base/redirect-folder.html       301 /base/redirect-folder → 301 /base/redirect-folder/ → 404 404.html
+        /base/redirect-folder.html       301 /base/redirect-folder.html/ → 200 redirect-folder.html/index.html
         /base/redirect-folder.html/      200 redirect-folder.html/index.html
-        /base/redirect-file.html         301 /base/redirect-file → 301 /base/redirect-file/ → 404 404.html
+        /base/redirect-file.html         301 /base/redirect-file.html/ → 200 redirect-file.html.html
         /base/redirect-file.html/        200 redirect-file.html.html
         /base/file?query=1               301 /base/file/?query=1 → 200 file.html
         /base/file/?query=1              200 file.html
@@ -477,10 +477,10 @@ describe('createServeRequestHandler', () => {
         /base/missing                    404 404.html
         /base/missing/                   301 /base/missing → 404 404.html
         /base/missing.html               301 /base/missing → 404 404.html
-        /base/redirect-folder.html       301 /base/redirect-folder → 404 404.html
-        /base/redirect-folder.html/      301 /base/redirect-folder.html → 301 /base/redirect-folder → 404 404.html
-        /base/redirect-file.html         301 /base/redirect-file → 404 404.html
-        /base/redirect-file.html/        301 /base/redirect-file.html → 301 /base/redirect-file → 404 404.html
+        /base/redirect-folder.html       200 redirect-folder.html/index.html
+        /base/redirect-folder.html/      301 /base/redirect-folder.html → 200 redirect-folder.html/index.html
+        /base/redirect-file.html         200 redirect-file.html.html
+        /base/redirect-file.html/        301 /base/redirect-file.html → 200 redirect-file.html.html
         /base/file?query=1               200 file.html
         /base/file/?query=1              301 /base/file?query=1 → 200 file.html
         /base/file.html?query=1          200 file.html
@@ -837,27 +837,25 @@ describe('createServeRequestHandler', () => {
       );
     });
 
-    // TODO fix: "200 redirect-folder.html/index.html"
     // plugin-client-redirects writes it for redirects from /redirect-folder.html
-    it('serves no client redirect folder of .html paths', async () => {
+    it('serves the client redirect folder of .html paths', async () => {
       await expect(
         serveRequest(
           {baseUrl: '/base/', trailingSlash: undefined},
           '/base/redirect-folder.html',
         ),
-      ).resolves.toBe('301 /base/redirect-folder → 404 404.html');
+      ).resolves.toBe('200 redirect-folder.html/index.html');
     });
 
-    // TODO fix: "200 redirect-file.html.html"
     // plugin-client-redirects writes it for redirects from /redirect-file.html,
     // with trailingSlash false
-    it('serves no client redirect file of .html paths', async () => {
+    it('serves the client redirect file of .html paths', async () => {
       await expect(
         serveRequest(
           {baseUrl: '/base/', trailingSlash: false},
           '/base/redirect-file.html',
         ),
-      ).resolves.toBe('301 /base/redirect-file → 404 404.html');
+      ).resolves.toBe('200 redirect-file.html.html');
     });
 
     // Like the malformed percent-encodings
diff --git a/packages/docusaurus/src/commands/serve/requestHandler.ts b/packages/docusaurus/src/commands/serve/requestHandler.ts
index 92c7426a900f..24f238478802 100644
--- a/packages/docusaurus/src/commands/serve/requestHandler.ts
+++ b/packages/docusaurus/src/commands/serve/requestHandler.ts
@@ -74,6 +74,9 @@ export function createServeRequestHandler({
     // Requests without url were redirected to the baseUrl
     req.url = req.url!.replace(baseUrl, '/');
 
+    // serve-handler can't serve these pages: cleanUrls would redirect them
+    req.url = (await getHtmlPathPageFileUrl(outDir, req.url)) ?? req.url;
+
     await serveHandler(req, res, {
       // cleanUrls serves /file with file.html, but also redirects /file.html
       // to /file, even when the file exists, and drops the baseUrl
@@ -139,12 +142,15 @@ async function getRedirectLocation(
   }
 
   // Static hosts serve the existing .html files, without clean URL redirects
-  if (await isHtmlFileRequest(outDir, url.slice(baseUrl.length - 1))) {
+  const outDirUrl = url.slice(baseUrl.length - 1);
+  if (await isHtmlFileRequest(outDir, outDirUrl)) {
     return undefined;
   }
 
+  const isHtmlPathPage =
+    (await getHtmlPathPageFileUrl(outDir, outDirUrl)) !== undefined;
   const cleanPathname = getCleanPathname(pathname, baseUrl);
-  if (pathname !== cleanPathname) {
+  if (!isHtmlPathPage && pathname !== cleanPathname) {
     return serializeURLPath({pathname: cleanPathname, search});
   }
 
@@ -197,6 +203,27 @@ function hasNullByte(url: string): boolean {
   return pathname.includes('%00');
 }
 
+// The page of a .html path that isn't a file, like the client redirect files
+// "old-page.html/index.html", or "old-page.html.html" with trailingSlash false
+// See https://github.com/meta/docusaurus/pull/12920
+async function getHtmlPathPageFileUrl(
+  outDir: string,
+  url: string,
+): Promise<string | undefined> {
+  const pathname = url.split(/[?#]/)[0]!;
+  if (!pathname.endsWith('.html')) {
+    return undefined;
+  }
+  const queryAndHash = url.slice(pathname.length);
+  const pageFileUrls = [`${pathname}/index.html`, `${pathname}.html`];
+  for (const pageFileUrl of pageFileUrls) {
+    if (await isHtmlFileRequest(outDir, pageFileUrl)) {
+      return pageFileUrl + queryAndHash;
+    }
+  }
+  return undefined;
+}
+
 // The decoded paths that serve-handler's cleanUrls redirects
 function hasCleanUrlSuffix(url: string): boolean {
   const pathname = url.split(/[?#]/)[0]!;
@@ -231,7 +258,7 @@ async function isHtmlFileRequest(
   if (!filePath?.endsWith('.html')) {
     return false;
   }
-  // Not a folder, like the client redirect file "legacy.html/index.html"
+  // Not a folder, like the client redirect file "old-page.html/index.html"
   const stats = await fs.stat(filePath).catch(() => undefined);
   return stats?.isFile() ?? false;
 }