diff --git a/Lib/ctypes/__init__.py b/Lib/ctypes/__init__.py
index 0d86078..b768cb4 100644
--- a/Lib/ctypes/__init__.py
+++ b/Lib/ctypes/__init__.py
@@ -139,6 +139,9 @@ from _ctypes import sizeof, byref, addressof, alignment, resize
 from _ctypes import get_errno, set_errno
 from _ctypes import _SimpleCData
 
+from typing import Buffer
+Buffer.register(_SimpleCData)
+
 def _check_size(typ, typecode=None):
     # Check if sizeof(ctypes_type) against struct.calcsize.  This
     # should protect somewhat against a misconfigured libffi.
diff --git a/Lib/io.py b/Lib/io.py
index e03db97..46de8ec 100644
--- a/Lib/io.py
+++ b/Lib/io.py
@@ -50,6 +50,7 @@ __all__ = ["BlockingIOError", "open", "IOBase", "RawIOBase", "FileIO",
 
 import _io
 import abc
+import typing
 
 from _io import (DEFAULT_BUFFER_SIZE, BlockingIOError, UnsupportedOperation,
                  open, FileIO, BytesIO, StringIO, BufferedReader,
@@ -90,3 +91,5 @@ for klass in (BytesIO, BufferedReader, BufferedWriter, BufferedRandom,
 for klass in (StringIO, TextIOWrapper):
     TextIOBase.register(klass)
 del klass
+
+typing.Buffer.register(BytesIO)
diff --git a/Lib/test/test_typing.py b/Lib/test/test_typing.py
index a7f8dd5..be28f3e 100644
--- a/Lib/test/test_typing.py
+++ b/Lib/test/test_typing.py
@@ -596,6 +596,19 @@ class ProtocolTests(BaseTestCase):
         with self.assertRaises(TypeError):
             isinstance(0, typing.SupportsAbs)
 
+    def test_buffer(self):
+        from io import BytesIO
+        from ctypes import _SimpleCData
+        from mmap import mmap
+        from array import array
+        self.assertIsSubclass(bytes, typing.Buffer)
+        self.assertIsSubclass(bytearray, typing.Buffer)
+        self.assertIsSubclass(memoryview, typing.Buffer)
+        self.assertIsSubclass(BytesIO, typing.Buffer)
+        self.assertIsSubclass(_SimpleCData, typing.Buffer)
+        self.assertIsSubclass(mmap.mmap, typing.Buffer)
+        self.assertIsSubclass(array, typing.Buffer)
+
 
 class GenericTests(BaseTestCase):
 
diff --git a/Lib/typing.py b/Lib/typing.py
index 4cac66c..e4d65e8 100644
--- a/Lib/typing.py
+++ b/Lib/typing.py
@@ -46,6 +46,7 @@ __all__ = [
     'ValuesView',
 
     # Structural checks, a.k.a. protocols.
+    'Buffer',
     'Reversible',
     'SupportsAbs',
     'SupportsFloat',
@@ -1359,6 +1360,17 @@ else:
     AsyncIterator = None
 
 
+class Buffer(metaclass=abc.ABCMeta):
+    """Objects supporting the PEP-3118 buffer interface"""
+    __slots__ = ()
+    # Non generic
+    # No defined python API (buffer object interface is defined at a C level)
+
+Buffer.register(type(b''))
+Buffer.register(type(bytearray()))
+Buffer.register(type(memoryview(b'')))
+# TODO: array module, mmap module,
+
 class Iterable(Generic[T_co], extra=collections_abc.Iterable):
     __slots__ = ()