diff --git a/Lib/ntpath.py b/Lib/ntpath.py
index 1b1873f08b608b..5309f41e386c60 100644
--- a/Lib/ntpath.py
+++ b/Lib/ntpath.py
@@ -243,9 +243,15 @@ def split(p):
 def splitext(p):
     p = os.fspath(p)
     if isinstance(p, bytes):
-        return genericpath._splitext(p, b'\\', b'/', b'.')
+        prefixes = (b'\\\\', b'//', b'\\/', b'/\\')
+        root, ext = genericpath._splitext(p, b'\\', b'/', b'.')
     else:
-        return genericpath._splitext(p, '\\', '/', '.')
+        prefixes = ('\\\\', '//', '\\/', '/\\')
+        root, ext = genericpath._splitext(p, '\\', '/', '.')
+    if ext and root.startswith(prefixes) and not splitroot(root)[2]:
+        # \\server.ext or \\server\share.ext, but not \\server\share\path.ext
+        return p, p[:0]
+    return root, ext
 splitext.__doc__ = genericpath._splitext.__doc__
 
 
diff --git a/Lib/test/test_ntpath.py b/Lib/test/test_ntpath.py
index 64cbfaaaaa0690..94d482abeee43a 100644
--- a/Lib/test/test_ntpath.py
+++ b/Lib/test/test_ntpath.py
@@ -100,6 +100,37 @@ def test_splitext(self):
         tester('ntpath.splitext("xx\\foo.bar.ext")', ('xx\\foo.bar', '.ext'))
         tester('ntpath.splitext("c:a/b\\c.d")', ('c:a/b\\c', '.d'))
 
+        tester(r'ntpath.splitext("\\server\share.ext")',
+               (r'\\server\share.ext', ''))
+        tester(r'ntpath.splitext("//server/share.ext")',
+               (r'//server/share.ext', ''))
+        tester(r'ntpath.splitext("\\server.ext")',
+               (r'\\server.ext', ''))
+        tester(r'ntpath.splitext("//server.ext")',
+               (r'//server.ext', ''))
+
+        tester(r'ntpath.splitext("\\?\UNC\server\share.ext")',
+               (r'\\?\UNC\server\share.ext', ''))
+        tester(r'ntpath.splitext("//?/UNC/server/share.ext")',
+               (r'//?/UNC/server/share.ext', ''))
+        tester(r'ntpath.splitext("\\?\UNC\server.ext")',
+               (r'\\?\UNC\server.ext', ''))
+        tester(r'ntpath.splitext("//?/UNC/server.ext")',
+               (r'//?/UNC/server.ext', ''))
+
+        tester(r'ntpath.splitext("\\server\share\file.ext")',
+               (r'\\server\share\file', '.ext'))
+        tester(r'ntpath.splitext("//server/share/file.ext")',
+               (r'//server/share/file', '.ext'))
+        tester(r'ntpath.splitext("\\server\share/file.ext")',
+               (r'\\server\share/file', '.ext'))
+        tester(r'ntpath.splitext("//server/share\file.ext")',
+               (r'//server/share\file', '.ext'))
+        tester(r'ntpath.splitext("\\?\UNC\server\share\file.ext")',
+               (r'\\?\UNC\server\share\file', '.ext'))
+        tester(r'ntpath.splitext("//?/UNC/server/share/file.ext")',
+               (r'//?/UNC/server/share/file', '.ext'))
+
     def test_splitdrive(self):
         tester("ntpath.splitdrive('')", ('', ''))
         tester("ntpath.splitdrive('foo')", ('', 'foo'))
diff --git a/Misc/NEWS.d/next/Library/2024-02-27-19-13-25.gh-issue-115892.JouB3p.rst b/Misc/NEWS.d/next/Library/2024-02-27-19-13-25.gh-issue-115892.JouB3p.rst
new file mode 100644
index 00000000000000..c0ad89a4b0c11c
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2024-02-27-19-13-25.gh-issue-115892.JouB3p.rst
@@ -0,0 +1,2 @@
+:func:`os.path.splitext` on Windows no longer splits an "extension" from the
+server or share name in the UNC path.