Issue #29011:  Fix an important omission by adding Deque to the typing module.
diff --git a/Lib/typing.py b/Lib/typing.py
index 34845b7..2821c3c 100644
--- a/Lib/typing.py
+++ b/Lib/typing.py
@@ -59,6 +59,7 @@
     'SupportsRound',
 
     # Concrete collection types.
+    'Deque',
     'Dict',
     'DefaultDict',
     'List',
@@ -1771,6 +1772,15 @@
                             "use list() instead")
         return _generic_new(list, cls, *args, **kwds)
 
+class Deque(collections.deque, MutableSequence[T], extra=collections.deque):
+
+    __slots__ = ()
+
+    def __new__(cls, *args, **kwds):
+        if _geqv(cls, Deque):
+            raise TypeError("Type Deque cannot be instantiated; "
+                            "use deque() instead")
+        return _generic_new(collections.deque, cls, *args, **kwds)
 
 class Set(set, MutableSet[T], extra=set):