diff --git a/changelog.d/9168.feature b/changelog.d/9168.feature
new file mode 100644
index 000000000..8be1950ee
--- /dev/null
+++ b/changelog.d/9168.feature
@@ -0,0 +1 @@
+Add an admin API for retrieving the current room state of a room.
\ No newline at end of file
diff --git a/docs/admin_api/rooms.md b/docs/admin_api/rooms.md
index f34cec1ff..3832b3640 100644
--- a/docs/admin_api/rooms.md
+++ b/docs/admin_api/rooms.md
@@ -368,6 +368,36 @@ Response:
 }
 ```
 
+# Room State API
+
+The Room State admin API allows server admins to get a list of all state events in a room.
+
+The response includes the following fields:
+
+* `state` - The current state of the room at the time of request.
+
+## Usage
+
+A standard request:
+
+```
+GET /_synapse/admin/v1/rooms/<room_id>/state
+
+{}
+```
+
+Response:
+
+```json
+{
+  "state": [
+    {"type": "m.room.create", "state_key": "", "etc": true},
+    {"type": "m.room.power_levels", "state_key": "", "etc": true},
+    {"type": "m.room.name", "state_key": "", "etc": true}
+  ]
+}
+```
+
 # Delete Room API
 
 The Delete Room admin API allows server admins to remove rooms from server
diff --git a/synapse/handlers/message.py b/synapse/handlers/message.py
index e2a7d567f..a15336bf0 100644
--- a/synapse/handlers/message.py
+++ b/synapse/handlers/message.py
@@ -174,7 +174,7 @@ class MessageHandler:
                 raise NotFoundError("Can't find event for token %s" % (at_token,))
 
             visible_events = await filter_events_for_client(
-                self.storage, user_id, last_events, filter_send_to_client=False
+                self.storage, user_id, last_events, filter_send_to_client=False,
             )
 
             event = last_events[0]
diff --git a/synapse/rest/admin/__init__.py b/synapse/rest/admin/__init__.py
index 57e0a1083..f5c5d164f 100644
--- a/synapse/rest/admin/__init__.py
+++ b/synapse/rest/admin/__init__.py
@@ -44,6 +44,7 @@ from synapse.rest.admin.rooms import (
     MakeRoomAdminRestServlet,
     RoomMembersRestServlet,
     RoomRestServlet,
+    RoomStateRestServlet,
     ShutdownRoomRestServlet,
 )
 from synapse.rest.admin.server_notice_servlet import SendServerNoticeServlet
@@ -213,6 +214,7 @@ def register_servlets(hs, http_server):
     """
     register_servlets_for_client_rest_resource(hs, http_server)
     ListRoomRestServlet(hs).register(http_server)
+    RoomStateRestServlet(hs).register(http_server)
     RoomRestServlet(hs).register(http_server)
     RoomMembersRestServlet(hs).register(http_server)
     DeleteRoomRestServlet(hs).register(http_server)
diff --git a/synapse/rest/admin/rooms.py b/synapse/rest/admin/rooms.py
index f14915d47..3e57e6a4d 100644
--- a/synapse/rest/admin/rooms.py
+++ b/synapse/rest/admin/rooms.py
@@ -292,6 +292,45 @@ class RoomMembersRestServlet(RestServlet):
         return 200, ret
 
 
+class RoomStateRestServlet(RestServlet):
+    """
+    Get full state within a room.
+    """
+
+    PATTERNS = admin_patterns("/rooms/(?P<room_id>[^/]+)/state")
+
+    def __init__(self, hs: "HomeServer"):
+        self.hs = hs
+        self.auth = hs.get_auth()
+        self.store = hs.get_datastore()
+        self.clock = hs.get_clock()
+        self._event_serializer = hs.get_event_client_serializer()
+
+    async def on_GET(
+        self, request: SynapseRequest, room_id: str
+    ) -> Tuple[int, JsonDict]:
+        requester = await self.auth.get_user_by_req(request)
+        await assert_user_is_admin(self.auth, requester.user)
+
+        ret = await self.store.get_room(room_id)
+        if not ret:
+            raise NotFoundError("Room not found")
+
+        event_ids = await self.store.get_current_state_ids(room_id)
+        events = await self.store.get_events(event_ids.values())
+        now = self.clock.time_msec()
+        room_state = await self._event_serializer.serialize_events(
+            events.values(),
+            now,
+            # We don't bother bundling aggregations in when asked for state
+            # events, as clients won't use them.
+            bundle_aggregations=False,
+        )
+        ret = {"state": room_state}
+
+        return 200, ret
+
+
 class JoinRoomAliasServlet(RestServlet):
 
     PATTERNS = admin_patterns("/join/(?P<room_identifier>[^/]*)")
diff --git a/tests/rest/admin/test_room.py b/tests/rest/admin/test_room.py
index a0f32c551..7c47aa7e0 100644
--- a/tests/rest/admin/test_room.py
+++ b/tests/rest/admin/test_room.py
@@ -1180,6 +1180,21 @@ class RoomTestCase(unittest.HomeserverTestCase):
         )
         self.assertEqual(channel.json_body["total"], 3)
 
+    def test_room_state(self):
+        """Test that room state can be requested correctly"""
+        # Create two test rooms
+        room_id = self.helper.create_room_as(self.admin_user, tok=self.admin_user_tok)
+
+        url = "/_synapse/admin/v1/rooms/%s/state" % (room_id,)
+        channel = self.make_request(
+            "GET", url.encode("ascii"), access_token=self.admin_user_tok,
+        )
+        self.assertEqual(200, channel.code, msg=channel.json_body)
+        self.assertIn("state", channel.json_body)
+        # testing that the state events match is painful and not done here. We assume that
+        # the create_room already does the right thing, so no need to verify that we got
+        # the state events it created.
+
 
 class JoinAliasRoomTestCase(unittest.HomeserverTestCase):