diff --git a/ansible/roles/magnum/templates/magnum.conf.j2 b/ansible/roles/magnum/templates/magnum.conf.j2
index 7e143d7ed8..eb85ae7497 100644
--- a/ansible/roles/magnum/templates/magnum.conf.j2
+++ b/ansible/roles/magnum/templates/magnum.conf.j2
@@ -75,6 +75,7 @@ memcached_servers = {% for host in groups['memcached'] %}{{ 'api' | kolla_addres
 trustee_domain_admin_password = {{ magnum_keystone_password }}
 trustee_domain_admin_name = {{ magnum_trustee_domain_admin }}
 trustee_domain_name = {{ magnum_trustee_domain }}
+trustee_keystone_region_name = {{ openstack_region_name }}
 cluster_user_trust = {{ enable_cluster_user_trust }}
 
 [oslo_concurrency]
diff --git a/releasenotes/notes/magnum-trustee-keystone-region-name-002162a45f855faf.yaml b/releasenotes/notes/magnum-trustee-keystone-region-name-002162a45f855faf.yaml
new file mode 100644
index 0000000000..3c271bd0b8
--- /dev/null
+++ b/releasenotes/notes/magnum-trustee-keystone-region-name-002162a45f855faf.yaml
@@ -0,0 +1,4 @@
+---
+fixes:
+  - |
+    Fixes Magnum trust operations in multi-region deployments.