diff --git a/changelog.d/4896.feature b/changelog.d/4896.feature
new file mode 100644
index 0000000000..46ac49a4b4
--- /dev/null
+++ b/changelog.d/4896.feature
@@ -0,0 +1 @@
+Add option to disable searching of local and remote public room lists.
diff --git a/docs/sample_config.yaml b/docs/sample_config.yaml
index f6f6aec7cf..4ada0fba0e 100644
--- a/docs/sample_config.yaml
+++ b/docs/sample_config.yaml
@@ -1049,6 +1049,12 @@ password_config:
 
 
 
+# Uncomment to disable searching the public room list. When disabled
+# blocks searching local and remote room lists for local and remote
+# users by always returning an empty list for all queries.
+#
+#enable_room_list_search: false
+
 # The `alias_creation` option controls who's allowed to create aliases
 # on this server.
 #
diff --git a/synapse/config/room_directory.py b/synapse/config/room_directory.py
index 9b897abe3c..8a9fded4c5 100644
--- a/synapse/config/room_directory.py
+++ b/synapse/config/room_directory.py
@@ -20,6 +20,10 @@ from ._base import Config, ConfigError
 
 class RoomDirectoryConfig(Config):
     def read_config(self, config):
+        self.enable_room_list_search = config.get(
+            "enable_room_list_search", True,
+        )
+
         alias_creation_rules = config.get("alias_creation_rules")
 
         if alias_creation_rules is not None:
@@ -54,6 +58,12 @@ class RoomDirectoryConfig(Config):
 
     def default_config(self, config_dir_path, server_name, **kwargs):
         return """
+        # Uncomment to disable searching the public room list. When disabled
+        # blocks searching local and remote room lists for local and remote
+        # users by always returning an empty list for all queries.
+        #
+        #enable_room_list_search: false
+
         # The `alias_creation` option controls who's allowed to create aliases
         # on this server.
         #
diff --git a/synapse/handlers/directory.py b/synapse/handlers/directory.py
index 8b113307d2..fe128d9c88 100644
--- a/synapse/handlers/directory.py
+++ b/synapse/handlers/directory.py
@@ -44,6 +44,7 @@ class DirectoryHandler(BaseHandler):
         self.appservice_handler = hs.get_application_service_handler()
         self.event_creation_handler = hs.get_event_creation_handler()
         self.config = hs.config
+        self.enable_room_list_search = hs.config.enable_room_list_search
 
         self.federation = hs.get_federation_client()
         hs.get_federation_registry().register_query_handler(
@@ -411,6 +412,13 @@ class DirectoryHandler(BaseHandler):
         if visibility not in ["public", "private"]:
             raise SynapseError(400, "Invalid visibility setting")
 
+        if visibility == "public" and not self.enable_room_list_search:
+            # The room list has been disabled.
+            raise AuthError(
+                403,
+                "This user is not permitted to publish rooms to the room list"
+            )
+
         room = yield self.store.get_room(room_id)
         if room is None:
             raise SynapseError(400, "Unknown room")
diff --git a/synapse/handlers/room_list.py b/synapse/handlers/room_list.py
index afa508d729..d6c9d56007 100644
--- a/synapse/handlers/room_list.py
+++ b/synapse/handlers/room_list.py
@@ -44,6 +44,7 @@ EMPTY_THIRD_PARTY_ID = ThirdPartyInstanceID(None, None)
 class RoomListHandler(BaseHandler):
     def __init__(self, hs):
         super(RoomListHandler, self).__init__(hs)
+        self.enable_room_list_search = hs.config.enable_room_list_search
         self.response_cache = ResponseCache(hs, "room_list")
         self.remote_response_cache = ResponseCache(hs, "remote_room_list",
                                                    timeout_ms=30 * 1000)
@@ -66,10 +67,17 @@ class RoomListHandler(BaseHandler):
                 appservice and network id to use an appservice specific one.
                 Setting to None returns all public rooms across all lists.
         """
+        if not self.enable_room_list_search:
+            return defer.succeed({
+                "chunk": [],
+                "total_room_count_estimate": 0,
+            })
+
         logger.info(
             "Getting public room list: limit=%r, since=%r, search=%r, network=%r",
             limit, since_token, bool(search_filter), network_tuple,
         )
+
         if search_filter:
             # We explicitly don't bother caching searches or requests for
             # appservice specific lists.
@@ -441,6 +449,12 @@ class RoomListHandler(BaseHandler):
     def get_remote_public_room_list(self, server_name, limit=None, since_token=None,
                                     search_filter=None, include_all_networks=False,
                                     third_party_instance_id=None,):
+        if not self.enable_room_list_search:
+            defer.returnValue({
+                "chunk": [],
+                "total_room_count_estimate": 0,
+            })
+
         if search_filter:
             # We currently don't support searching across federation, so we have
             # to do it manually without pagination
diff --git a/tests/handlers/test_directory.py b/tests/handlers/test_directory.py
index 9bf395e923..5b2105bc76 100644
--- a/tests/handlers/test_directory.py
+++ b/tests/handlers/test_directory.py
@@ -111,7 +111,7 @@ class TestCreateAliasACL(unittest.HomeserverTestCase):
 
     servlets = [directory.register_servlets, room.register_servlets]
 
-    def prepare(self, hs, reactor, clock):
+    def prepare(self, reactor, clock, hs):
         # We cheekily override the config to add custom alias creation rules
         config = {}
         config["alias_creation_rules"] = [
@@ -151,3 +151,60 @@ class TestCreateAliasACL(unittest.HomeserverTestCase):
         )
         self.render(request)
         self.assertEquals(200, channel.code, channel.result)
+
+
+class TestRoomListSearchDisabled(unittest.HomeserverTestCase):
+    user_id = "@test:test"
+
+    servlets = [directory.register_servlets, room.register_servlets]
+
+    def prepare(self, reactor, clock, hs):
+        room_id = self.helper.create_room_as(self.user_id)
+
+        request, channel = self.make_request(
+            "PUT",
+            b"directory/list/room/%s" % (room_id.encode('ascii'),),
+            b'{}',
+        )
+        self.render(request)
+        self.assertEquals(200, channel.code, channel.result)
+
+        self.room_list_handler = hs.get_room_list_handler()
+        self.directory_handler = hs.get_handlers().directory_handler
+
+        return hs
+
+    def test_disabling_room_list(self):
+        self.room_list_handler.enable_room_list_search = True
+        self.directory_handler.enable_room_list_search = True
+
+        # Room list is enabled so we should get some results
+        request, channel = self.make_request(
+            "GET",
+            b"publicRooms",
+        )
+        self.render(request)
+        self.assertEquals(200, channel.code, channel.result)
+        self.assertTrue(len(channel.json_body["chunk"]) > 0)
+
+        self.room_list_handler.enable_room_list_search = False
+        self.directory_handler.enable_room_list_search = False
+
+        # Room list disabled so we should get no results
+        request, channel = self.make_request(
+            "GET",
+            b"publicRooms",
+        )
+        self.render(request)
+        self.assertEquals(200, channel.code, channel.result)
+        self.assertTrue(len(channel.json_body["chunk"]) == 0)
+
+        # Room list disabled so we shouldn't be allowed to publish rooms
+        room_id = self.helper.create_room_as(self.user_id)
+        request, channel = self.make_request(
+            "PUT",
+            b"directory/list/room/%s" % (room_id.encode('ascii'),),
+            b'{}',
+        )
+        self.render(request)
+        self.assertEquals(403, channel.code, channel.result)
diff --git a/tests/utils.py b/tests/utils.py
index eeb4bce5a2..d4ab4209ed 100644
--- a/tests/utils.py
+++ b/tests/utils.py
@@ -280,7 +280,6 @@ def setup_test_homeserver(
             db_config=config.database_config,
             version_string="Synapse/tests",
             database_engine=db_engine,
-            room_list_handler=object(),
             tls_server_context_factory=Mock(),
             tls_client_options_factory=Mock(),
             reactor=reactor,
@@ -351,7 +350,6 @@ def setup_test_homeserver(
             config=config,
             version_string="Synapse/tests",
             database_engine=db_engine,
-            room_list_handler=object(),
             tls_server_context_factory=Mock(),
             tls_client_options_factory=Mock(),
             reactor=reactor,