diff --git a/Lib/ntpath.py b/Lib/ntpath.py
index b3c23f0abc2d889..6649298f9f67850 100644
--- a/Lib/ntpath.py
+++ b/Lib/ntpath.py
@@ -666,6 +666,7 @@ def realpath(path, /, *, strict=False):
             prefix = b'\\\\?\\'
             unc_prefix = b'\\\\?\\UNC\\'
             new_unc_prefix = b'\\\\'
+            colon_sep = b':\\'
             cwd = os.getcwdb()
             # bpo-38081: Special case for realpath(b'nul')
             devnull = b'nul'
@@ -675,6 +676,7 @@ def realpath(path, /, *, strict=False):
             prefix = '\\\\?\\'
             unc_prefix = '\\\\?\\UNC\\'
             new_unc_prefix = '\\\\'
+            colon_sep = ':\\'
             cwd = os.getcwd()
             # bpo-38081: Special case for realpath('nul')
             devnull = 'nul'
@@ -718,25 +720,29 @@ def realpath(path, /, *, strict=False):
         # strip off that prefix unless it was already provided on the original
         # path.
         if not had_prefix and path.startswith(prefix):
-            # For UNC paths, the prefix will actually be \\?\UNC\
-            # Handle that case as well.
+            # For UNC drives, the path starts with \\?\UNC\.
             if path.startswith(unc_prefix):
                 spath = new_unc_prefix + path[len(unc_prefix):]
-            else:
+            # For drive-letter drives, the path starts with \\?\<letter>:\.
+            elif path.startswith(colon_sep, len(prefix) + 1):
                 spath = path[len(prefix):]
-            # Ensure that the non-prefixed path resolves to the same path
-            try:
-                if _getfinalpathname(spath) == path:
-                    path = spath
-            except ValueError:
-                # Unexpected, as an invalid path should not have gained a prefix
-                # at any point, but we ignore this error just in case.
-                pass
-            except OSError as ex:
-                # If the path does not exist and originally did not exist, then
-                # strip the prefix anyway.
-                if ex.winerror == initial_winerror:
-                    path = spath
+            # For all others, e.g. volume GUID paths, it cannot be stripped.
+            else:
+                spath = None
+            if spath is not None:
+                # Ensure that the non-prefixed path resolves to the same path
+                try:
+                    if _getfinalpathname(spath) == path:
+                        path = spath
+                except ValueError:
+                    # Unexpected, as an invalid path should not have gained a
+                    # prefix at any point, but we ignore this error just in case.
+                    pass
+                except OSError as ex:
+                    # If the path does not exist and originally did not exist,
+                    # then strip the prefix anyway.
+                    if ex.winerror == initial_winerror:
+                        path = spath
         return path
 
 
diff --git a/Lib/test/test_ntpath.py b/Lib/test/test_ntpath.py
index 936332bf94ffe77..df7bb011ede208e 100644
--- a/Lib/test/test_ntpath.py
+++ b/Lib/test/test_ntpath.py
@@ -1535,6 +1535,33 @@ def test_isjunction(self):
                 self.assertFalse(ntpath.isjunction('tmpdir'))
                 self.assertPathEqual(ntpath.realpath('testjunc'), ntpath.realpath('tmpdir'))
 
+    @unittest.skipIf(sys.platform != 'win32', "Can only test junctions with creation on win32.")
+    def test_realpath_volume_guid_path(self):
+        # gh-89760: the \\?\ prefix cannot be stripped from a volume GUID path.
+        # Find a volume which is not mounted as a drive.
+        for volume in os.listvolumes():
+            if not os.listmounts(volume):
+                break
+        else:
+            raise unittest.SkipTest('no volume without a mount point')
+
+        with os_helper.temp_dir() as d:
+            with os_helper.change_cwd(d):
+                # _winapi.CreateJunction() adds the \\??\\ prefix to a path
+                # which already has a prefix.
+                try:
+                    subprocess.run(['cmd', '/c', 'mklink', '/j',
+                                    'testjunc', volume],
+                                   check=True, capture_output=True)
+                except (OSError, subprocess.CalledProcessError):
+                    raise unittest.SkipTest('creating the test junction failed')
+
+                for path in 'testjunc', 'testjunc/spam', 'testjunc/spam/eggs':
+                    with self.subTest(path=path):
+                        realpath = ntpath.realpath(path)
+                        self.assertStartsWith(realpath, '\\\\?\\Volume{')
+                        self.assertTrue(ntpath.isabs(realpath), realpath)
+
     def test_isfile_invalid_paths(self):
         isfile = ntpath.isfile
         self.assertIs(isfile('/tmp\udfffabcds'), False)
diff --git a/Misc/NEWS.d/next/Library/2026-08-09-00-30-00.gh-issue-89760.rpvol.rst b/Misc/NEWS.d/next/Library/2026-08-09-00-30-00.gh-issue-89760.rpvol.rst
new file mode 100644
index 000000000000000..9218ecfe9ce62e3
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2026-08-09-00-30-00.gh-issue-89760.rpvol.rst
@@ -0,0 +1,2 @@
+Fix :func:`os.path.realpath` on Windows: the ``\\?\`` prefix is no longer
+stripped from a volume GUID path, which made the result invalid.