diff --git a/synapse/handlers/groups_local.py b/synapse/handlers/groups_local.py
index df29edeb83..a2f16f77df 100644
--- a/synapse/handlers/groups_local.py
+++ b/synapse/handlers/groups_local.py
@@ -365,6 +365,32 @@ class GroupsLocalHandler(GroupsLocalWorkerHandler):
 
         return {}
 
+    async def force_join_user_to_group(self, group_id, user_id):
+        """Forces a user to join a group.
+        """
+        if not self.is_mine_id(group_id):
+            raise SynapseError(400, "Can only affect local groups")
+
+        if not self.is_mine_id(user_id):
+            raise SynapseError(400, "Can only affect local users")
+
+        # Bypass the group server to avoid business logic regarding whether or not
+        # the user can actually join.
+        await self.store.add_user_to_group(group_id, user_id)
+
+        token = await self.store.register_user_group_membership(
+            group_id,
+            user_id,
+            membership="join",
+            is_admin=False,
+            local_attestation=None,
+            remote_attestation=None,
+            is_publicised=False,
+        )
+        self.notifier.on_new_event("groups_key", token, users=[user_id])
+
+        return {}
+
     async def accept_invite(self, group_id, user_id, content):
         """Accept an invite to a group
         """
diff --git a/synapse/rest/admin/__init__.py b/synapse/rest/admin/__init__.py
index 6f7dc06503..b7121c0c26 100644
--- a/synapse/rest/admin/__init__.py
+++ b/synapse/rest/admin/__init__.py
@@ -31,7 +31,11 @@ from synapse.rest.admin.event_reports import (
     EventReportDetailRestServlet,
     EventReportsRestServlet,
 )
-from synapse.rest.admin.groups import DeleteGroupAdminRestServlet
+from synapse.rest.admin.groups import (
+    DeleteGroupAdminRestServlet,
+    ForceJoinGroupAdminRestServlet,
+    UpdatePublicityGroupAdminRestServlet,
+)
 from synapse.rest.admin.media import ListMediaInRoom, register_servlets_for_media_repo
 from synapse.rest.admin.purge_room_servlet import PurgeRoomServlet
 from synapse.rest.admin.rooms import (
@@ -244,6 +248,8 @@ def register_servlets_for_client_rest_resource(hs, http_server):
     ShutdownRoomRestServlet(hs).register(http_server)
     UserRegisterServlet(hs).register(http_server)
     DeleteGroupAdminRestServlet(hs).register(http_server)
+    ForceJoinGroupAdminRestServlet(hs).register(http_server)
+    UpdatePublicityGroupAdminRestServlet(hs).register(http_server)
     AccountValidityRenewServlet(hs).register(http_server)
 
     # Load the media repo ones if we're using them. Otherwise load the servlets which
diff --git a/synapse/rest/admin/groups.py b/synapse/rest/admin/groups.py
index d0c86b204a..55ad392944 100644
--- a/synapse/rest/admin/groups.py
+++ b/synapse/rest/admin/groups.py
@@ -15,7 +15,7 @@
 import logging
 
 from synapse.api.errors import SynapseError
-from synapse.http.servlet import RestServlet
+from synapse.http.servlet import assert_params_in_dict, parse_json_object_from_request, RestServlet
 from synapse.rest.admin._base import admin_patterns, assert_user_is_admin
 
 logger = logging.getLogger(__name__)
@@ -41,3 +41,57 @@ class DeleteGroupAdminRestServlet(RestServlet):
 
         await self.group_server.delete_group(group_id, requester.user.to_string())
         return 200, {}
+
+
+class ForceJoinGroupAdminRestServlet(RestServlet):
+    """Allows a server admin to force-join a local user to a local group.
+    """
+
+    PATTERNS = admin_patterns("/group/(?P<group_id>[^/]*)/force_join$")
+
+    def __init__(self, hs):
+        self.groups_handler = hs.get_groups_local_handler()
+        self.is_mine_id = hs.is_mine_id
+        self.auth = hs.get_auth()
+
+    async def on_POST(self, request, group_id):
+        requester = await self.auth.get_user_by_req(request)
+        await assert_user_is_admin(self.auth, requester.user)
+
+        if not self.is_mine_id(group_id):
+            raise SynapseError(400, "Can only affect local groups")
+
+        body = parse_json_object_from_request(request, allow_empty_body=False)
+        assert_params_in_dict(body, ["user_id"])
+        target_user_id = body["user_id"]
+        await self.groups_handler.force_join_user_to_group(group_id, target_user_id)
+
+        return 200, {}
+
+
+class UpdatePublicityGroupAdminRestServlet(RestServlet):
+    """Allows a server admin to update a user's publicity (flair) for a given group.
+    """
+
+    PATTERNS = admin_patterns("/group/(?P<group_id>[^/]*)/update_publicity$")
+
+    def __init__(self, hs):
+        self.store = hs.get_datastore()
+        self.is_mine_id = hs.is_mine_id
+        self.auth = hs.get_auth()
+
+    async def on_POST(self, request, group_id):
+        requester = await self.auth.get_user_by_req(request)
+        await assert_user_is_admin(self.auth, requester.user)
+
+        body = parse_json_object_from_request(request, allow_empty_body=False)
+        assert_params_in_dict(body, ["user_id"])
+        target_user_id = body["user_id"]
+        if not self.is_mine_id(target_user_id):
+            raise SynapseError(400, "Can only affect local users")
+
+        # Logic copied from `/self/update_publicity` endpoint.
+        publicise = body["publicise"]
+        await self.store.update_group_publicity(group_id, target_user_id, publicise)
+
+        return 200, {}