diff --git a/django/forms/widgets.py b/django/forms/widgets.py
index 896984dc08..c744d090ad 100644
--- a/django/forms/widgets.py
+++ b/django/forms/widgets.py
@@ -521,6 +521,13 @@ class Select(Widget):
         # more than once.
         self.choices = list(choices)
 
+    def __deepcopy__(self, memo):
+        obj = copy.copy(self)
+        obj.attrs = self.attrs.copy()
+        obj.choices = copy.copy(self.choices)
+        memo[id(self)] = obj
+        return obj
+
     def render(self, name, value, attrs=None, choices=()):
         if value is None:
             value = ''
diff --git a/tests/forms_tests/tests/test_widgets.py b/tests/forms_tests/tests/test_widgets.py
index 40ff750f60..2f1b6e48f7 100644
--- a/tests/forms_tests/tests/test_widgets.py
+++ b/tests/forms_tests/tests/test_widgets.py
@@ -1997,3 +1997,18 @@ class SelectDateWidgetTests(SimpleTestCase):
         # label tag is correctly associated with first rendered dropdown
         a = GetDate({'mydate_month': '1', 'mydate_day': '1', 'mydate_year': '2010'})
         self.assertIn('<label for="id_mydate_day">', a.as_p())
+
+
+class SelectWidgetTests(SimpleTestCase):
+
+    def test_deepcopy(self):
+        """
+        __deepcopy__() should copy all attributes properly (#25085).
+        """
+        widget = Select()
+        obj = copy.deepcopy(widget)
+        self.assertTrue(widget is not obj)
+        self.assertEqual(widget.choices, obj.choices)
+        self.assertTrue(widget.choices is not obj.choices)
+        self.assertEqual(widget.attrs, obj.attrs)
+        self.assertTrue(widget.attrs is not obj.attrs)