diff --git a/tests/storage/test_database.py b/tests/storage/test_database.py
index 8cd7c89ca2f8..8dcf7ef86fee 100644
--- a/tests/storage/test_database.py
+++ b/tests/storage/test_database.py
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from typing import Callable, Tuple
+from typing import Callable, Tuple, List
 from unittest.mock import Mock, call
 
 from twisted.internet import defer
@@ -29,6 +29,7 @@
 from synapse.util import Clock
 
 from tests import unittest
+from tests.utils import USE_POSTGRES_FOR_TESTS
 
 
 class TupleComparisonClauseTestCase(unittest.TestCase):
@@ -278,3 +279,49 @@ def _test_txn(txn: LoggingTransaction) -> None:
             ]
         )
         self.assertEqual(exception_callback.call_count, 6)  # no additional calls
+
+class PostgresReplicaIdentityTestCase(unittest.HomeserverTestCase):
+    if not USE_POSTGRES_FOR_TESTS:
+        skip = "Requires Postgres"
+
+    def prepare(
+        self, reactor: MemoryReactor, clock: Clock, homeserver: HomeServer
+    ) -> None:
+        self.db_pools = homeserver.get_datastores().databases
+
+    def test_all_tables_have_postgres_replica_identity(self) -> None:
+        """
+        Tests that all tables have a Postgres REPLICA IDENTITY.
+        (See #16224).
+
+        Tables with a PRIMARY KEY have an implied REPLICA IDENTITY and are fine.
+        Other tables need them to be set with `ALTER TABLE`.
+
+        A REPLICA IDENTITY is required for Postgres logical replication to work
+        properly without blocking updates and deletes.
+        """
+
+        sql = """
+            WITH tables_no_pkey AS (
+                SELECT tbl.table_schema, tbl.table_name
+                FROM information_schema.tables tbl
+                WHERE table_type = 'BASE TABLE'
+                    AND table_schema not in ('pg_catalog', 'information_schema')
+                    AND NOT EXISTS (
+                        SELECT 1 
+                        FROM information_schema.key_column_usage kcu
+                        WHERE kcu.table_name = tbl.table_name 
+                            AND kcu.table_schema = tbl.table_schema
+                    )
+            )
+            SELECT oid::regclass FROM tables_no_pkey INNER JOIN pg_class ON oid::regclass = table_name::regclass
+            WHERE relreplident = 'd';
+        """
+
+        def _list_tables_with_missing_replica_identities_txn(txn: LoggingTransaction) -> List[str]:
+            txn.execute(sql)
+            return [table_name for table_name, in txn]
+
+        for pool in self.db_pools:
+            missing = self.get_success(pool.runInteraction("test_list_missing_replica_identities", _list_tables_with_missing_replica_identities_txn))
+            self.assertTrue(len(missing) == 0, f"The following tables in the {pool.name()!r} database are missing REPLICA IDENTITIES: {missing!r}.")