diff --git a/Lib/test/test_types.py b/Lib/test/test_types.py
--- a/Lib/test/test_types.py
+++ b/Lib/test/test_types.py
@@ -7,6 +7,8 @@
 import sys
 import types
 import unittest
+import weakref
+
 
 class TypesTests(unittest.TestCase):
 
@@ -1169,6 +1171,13 @@
 
             self.assertEqual(ns, ns_roundtrip, pname)
 
+    def test_weakref(self):
+        original = types.SimpleNamespace()
+        weakns = weakref.ref(original)
+        ns = weakns()
+
+        self.assertIs(ns, original)
+
 
 def test_main():
     run_unittest(TypesTests, MappingProxyTests, ClassCreationTests,
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -254,6 +254,8 @@
 
 - Issue #15022: Add pickle and comparison support to types.SimpleNamespace.
 
+- Issue #15004: Add weakref support to types.SimpleNamespace.
+
 Library
 -------
 
diff --git a/Objects/namespaceobject.c b/Objects/namespaceobject.c
--- a/Objects/namespaceobject.c
+++ b/Objects/namespaceobject.c
@@ -7,6 +7,7 @@
 typedef struct {
     PyObject_HEAD
     PyObject *ns_dict;
+    PyObject *ns_weakreflist;
 } _PyNamespaceObject;
 
 
@@ -33,6 +34,9 @@
             return NULL;
         }
     }
+
+    ((_PyNamespaceObject *)self)->ns_weakreflist = NULL;
+
     return self;
 }
 
@@ -59,6 +63,9 @@
 static void
 namespace_dealloc(_PyNamespaceObject *ns)
 {
+    if (ns->ns_weakreflist != NULL)
+        PyObject_ClearWeakRefs((PyObject *)ns);
+
     PyObject_GC_UnTrack(ns);
     Py_CLEAR(ns->ns_dict);
     Py_TYPE(ns)->tp_free((PyObject *)ns);
@@ -227,7 +234,7 @@
     (traverseproc)namespace_traverse,           /* tp_traverse */
     (inquiry)namespace_clear,                   /* tp_clear */
     namespace_richcompare,                      /* tp_richcompare */
-    0,                                          /* tp_weaklistoffset */
+    offsetof(_PyNamespaceObject, ns_weakreflist), /* tp_weaklistoffset */
     0,                                          /* tp_iter */
     0,                                          /* tp_iternext */
     namespace_methods,                          /* tp_methods */