diff --git a/changelog.d/18284.misc b/changelog.d/18284.misc
new file mode 100644
index 0000000000..69610adc65
--- /dev/null
+++ b/changelog.d/18284.misc
@@ -0,0 +1 @@
+Add DB delta to remove the old state group deletion job.
diff --git a/synapse/storage/schema/state/delta/90/03_remove_old_deletion_bg_update.sql b/synapse/storage/schema/state/delta/90/03_remove_old_deletion_bg_update.sql
new file mode 100644
index 0000000000..1cc6d612b6
--- /dev/null
+++ b/synapse/storage/schema/state/delta/90/03_remove_old_deletion_bg_update.sql
@@ -0,0 +1,15 @@
+--
+-- This file is licensed under the Affero General Public License (AGPL) version 3.
+--
+-- Copyright (C) 2025 New Vector, Ltd
+--
+-- This program is free software: you can redistribute it and/or modify
+-- it under the terms of the GNU Affero General Public License as
+-- published by the Free Software Foundation, either version 3 of the
+-- License, or (at your option) any later version.
+--
+-- See the GNU Affero General Public License for more details:
+-- <https://www.gnu.org/licenses/agpl-3.0.html>.
+
+-- Remove the old unreferenced state group deletion background update if it exists
+DELETE FROM background_updates WHERE update_name = 'delete_unreferenced_state_groups_bg_update';