diff --git a/synapse/storage/databases/main/events_bg_updates.py b/synapse/storage/databases/main/events_bg_updates.py
index 584536111daa..9c194a79a6cc 100644
--- a/synapse/storage/databases/main/events_bg_updates.py
+++ b/synapse/storage/databases/main/events_bg_updates.py
@@ -17,7 +17,7 @@
 
 import attr
 
-from synapse.api.constants import EventContentFields, RelationTypes
+from synapse.api.constants import EventContentFields, EventTypes, RelationTypes
 from synapse.api.room_versions import KNOWN_ROOM_VERSIONS
 from synapse.events import make_event_from_dict
 from synapse.storage._base import SQLBaseStore, db_to_json, make_in_list_sql_clause
@@ -71,6 +71,10 @@ class _BackgroundUpdates:
 
     EVENTS_JUMP_TO_DATE_INDEX = "events_jump_to_date_index"
 
+    POPULATE_MEMBERSHIP_EVENT_STREAM_ORDERING = (
+        "populate_membership_event_stream_ordering"
+    )
+
 
 @attr.s(slots=True, frozen=True, auto_attribs=True)
 class _CalculateChainCover:
@@ -99,6 +103,10 @@ def __init__(
     ):
         super().__init__(database, db_conn, hs)
 
+        self.db_pool.updates.register_background_update_handler(
+            _BackgroundUpdates.POPULATE_MEMBERSHIP_EVENT_STREAM_ORDERING,
+            self._populate_membership_event_stream_ordering,
+        )
         self.db_pool.updates.register_background_update_handler(
             _BackgroundUpdates.EVENT_ORIGIN_SERVER_TS_NAME,
             self._background_reindex_origin_server_ts,
@@ -1498,3 +1506,97 @@ def _populate_txn(txn: LoggingTransaction) -> bool:
             )
 
         return batch_size
+
+    async def _populate_membership_event_stream_ordering(
+        self, progress: JsonDict, batch_size: int
+    ) -> int:
+        def _populate_membership_event_stream_ordering(
+            txn: LoggingTransaction,
+        ) -> bool:
+
+            if "max_stream_ordering" in progress:
+                max_stream_ordering = progress["max_stream_ordering"]
+            else:
+                txn.execute("SELECT max(stream_ordering) FROM events")
+                res = txn.fetchone()
+                if res is None or res[0] is None:
+                    return True
+                else:
+                    max_stream_ordering = res[0]
+
+            start = progress.get("stream_ordering", 0)
+            stop = start + batch_size
+
+            sql = f"""
+                SELECT room_id, event_id, stream_ordering
+                FROM events
+                WHERE
+                    type = '{EventTypes.Member}'
+                    AND stream_ordering >= ?
+                    AND stream_ordering < ?
+            """
+            txn.execute(sql, (start, stop))
+
+            rows: List[Tuple[str, str, int]] = cast(
+                List[Tuple[str, str, int]], txn.fetchall()
+            )
+
+            event_ids: List[Tuple[str]] = []
+            event_stream_orderings: List[Tuple[int]] = []
+
+            for _, event_id, event_stream_ordering in rows:
+                event_ids.append((event_id,))
+                event_stream_orderings.append((event_stream_ordering,))
+
+            self.db_pool.simple_update_many_txn(
+                txn,
+                table="current_state_events",
+                key_names=("event_id",),
+                key_values=event_ids,
+                value_names=("event_stream_ordering",),
+                value_values=event_stream_orderings,
+            )
+
+            self.db_pool.simple_update_many_txn(
+                txn,
+                table="room_memberships",
+                key_names=("event_id",),
+                key_values=event_ids,
+                value_names=("event_stream_ordering",),
+                value_values=event_stream_orderings,
+            )
+
+            # NOTE: local_current_membership has no index on event_id, so only
+            # the room ID here will reduce the query rows read.
+            for room_id, event_id, event_stream_ordering in rows:
+                txn.execute(
+                    """
+                        UPDATE local_current_membership
+                        SET event_stream_ordering = ?
+                        WHERE room_id = ? AND event_id = ?
+                    """,
+                    (event_stream_ordering, room_id, event_id),
+                )
+
+            self.db_pool.updates._background_update_progress_txn(
+                txn,
+                _BackgroundUpdates.POPULATE_MEMBERSHIP_EVENT_STREAM_ORDERING,
+                {
+                    "stream_ordering": stop,
+                    "max_stream_ordering": max_stream_ordering,
+                },
+            )
+
+            return stop > max_stream_ordering
+
+        finished = await self.db_pool.runInteraction(
+            "_populate_membership_event_stream_ordering",
+            _populate_membership_event_stream_ordering,
+        )
+
+        if finished:
+            await self.db_pool.updates._end_background_update(
+                _BackgroundUpdates.POPULATE_MEMBERSHIP_EVENT_STREAM_ORDERING
+            )
+
+        return batch_size
diff --git a/synapse/storage/schema/main/delta/74/01membership_tables_event_stream_ordering.sql b/synapse/storage/schema/main/delta/74/01membership_tables_event_stream_ordering.sql
index 2de56447ad76..d313a1f311a4 100644
--- a/synapse/storage/schema/main/delta/74/01membership_tables_event_stream_ordering.sql
+++ b/synapse/storage/schema/main/delta/74/01membership_tables_event_stream_ordering.sql
@@ -16,3 +16,6 @@
 ALTER TABLE current_state_events ADD COLUMN event_stream_ordering BIGINT;
 ALTER TABLE local_current_membership ADD COLUMN event_stream_ordering BIGINT;
 ALTER TABLE room_memberships ADD COLUMN event_stream_ordering BIGINT;
+
+INSERT INTO background_updates (ordering, update_name, progress_json) VALUES
+  (7401, 'populate_membership_event_stream_ordering', '{}');