diff --git a/Lib/pathlib.py b/Lib/pathlib.py
index 5169ff5e633..ed31ddb8dd8 100644
--- a/Lib/pathlib.py
+++ b/Lib/pathlib.py
@@ -1425,3 +1425,9 @@ class PosixPath(Path, PurePosixPath):
 
 class WindowsPath(Path, PureWindowsPath):
     __slots__ = ()
+
+    def owner(self):
+        raise NotImplementedError("Path.owner() is unsupported on this system")
+
+    def group(self):
+        raise NotImplementedError("Path.group() is unsupported on this system")
diff --git a/Lib/test/test_pathlib.py b/Lib/test/test_pathlib.py
index 9a98d46c4e5..451e41f5ff1 100644
--- a/Lib/test/test_pathlib.py
+++ b/Lib/test/test_pathlib.py
@@ -1156,6 +1156,15 @@ class PureWindowsPathTest(_BasePurePathTest, unittest.TestCase):
         # UNC paths are never reserved
         self.assertIs(False, P('//my/share/nul/con/aux').is_reserved())
 
+    def test_owner(self):
+        P = self.cls
+        with self.assertRaises(NotImplementedError):
+            P('c:/').owner()
+
+    def test_group(self):
+        P = self.cls
+        with self.assertRaises(NotImplementedError):
+            P('c:/').group()
 
 class PurePathTest(_BasePurePathTest, unittest.TestCase):
     cls = pathlib.PurePath
diff --git a/Misc/NEWS b/Misc/NEWS
index 542af600053..45d8f2e2b65 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -201,6 +201,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #20589: Invoking Path.owner() and Path.group() on Windows now raise
+  NotImplementedError instead of ImportError.
+
 - Issue #26177: Fixed the keys() method for Canvas and Scrollbar widgets.
 
 - Issue #21042: Make ctypes.util.find_library() return the full path on