diff --git a/Lib/test/test_urllib.py b/Lib/test/test_urllib.py
index ab59727a8fd182..350cf4a73366c0 100644
--- a/Lib/test/test_urllib.py
+++ b/Lib/test/test_urllib.py
@@ -761,6 +761,17 @@ def hooktester(block_count, block_read_size, file_size, _report=report):
         self.assertEqual(report[1][1], 8192)
         self.assertEqual(report[2][1], 8192)
 
+    def test_file_url_no_filename(self):
+        # GH-156510: urlretrieve() with a file:// URL and no filename should
+        # return a valid local path, not a URL-formatted path with leading
+        # slashes that normpath() mishandles on Windows.
+        url = self.constructLocalFileUrl(os_helper.TESTFN)
+        filename, headers = urllib.request.urlretrieve(url)
+        self.assertEqual(
+            filename,
+            urllib.request.url2pathname(url, require_scheme=True, resolve_host=True),
+        )
+
 
 class urlretrieve_HttpTests(unittest.TestCase, FakeHTTPMixin):
     """Test urllib.urlretrieve() using fake http connections"""
diff --git a/Lib/urllib/request.py b/Lib/urllib/request.py
index 9fa92659a255ed..3d09370348432d 100644
--- a/Lib/urllib/request.py
+++ b/Lib/urllib/request.py
@@ -215,7 +215,7 @@ def urlretrieve(url, filename=None, reporthook=None, data=None):
         # Just return the local path and the "headers" for file://
         # URLs. No sense in performing a copy unless requested.
         if url_type == "file" and not filename:
-            return os.path.normpath(path), headers
+            return url2pathname(url, require_scheme=True, resolve_host=True), headers
 
         # Handle temporary file setup.
         if filename:
diff --git a/Misc/NEWS.d/next/Library/2026-08-29-11-58-00.gh-issue-156510.abCDef.rst b/Misc/NEWS.d/next/Library/2026-08-29-11-58-00.gh-issue-156510.abCDef.rst
new file mode 100644
index 00000000000000..9aeaa8350273af
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2026-08-29-11-58-00.gh-issue-156510.abCDef.rst
@@ -0,0 +1 @@
+Fix urllib.request.urlretrieve() with a local file:// URL and no explicit filename on Windows.