diff --git a/neutron/common/ovn/extensions.py b/neutron/common/ovn/extensions.py
index afd6bf4f900..3e48fe0e7f6 100644
--- a/neutron/common/ovn/extensions.py
+++ b/neutron/common/ovn/extensions.py
@@ -30,6 +30,7 @@ from neutron_lib.api.definitions import expose_port_forwarding_in_fip
 from neutron_lib.api.definitions import external_net
 from neutron_lib.api.definitions import extra_dhcp_opt
 from neutron_lib.api.definitions import extraroute
+from neutron_lib.api.definitions import extraroute_atomic
 from neutron_lib.api.definitions import filter_validation
 from neutron_lib.api.definitions import fip_pf_description
 from neutron_lib.api.definitions import fip_pf_detail
@@ -114,6 +115,7 @@ from neutron.extensions import security_groups_default_rules
 ML2_SUPPORTED_API_EXTENSIONS_OVN_L3 = [
     l3.ALIAS,
     extraroute.ALIAS,
+    extraroute_atomic.ALIAS,
     l3_ext_gw_mode.ALIAS,
     fip_pf_detail.ALIAS,
     fip_port_details.ALIAS,
diff --git a/releasenotes/notes/ovn-add-extension-extraroute-atomic-9959973ba162db83.yaml b/releasenotes/notes/ovn-add-extension-extraroute-atomic-9959973ba162db83.yaml
new file mode 100644
index 00000000000..2de65fbe5c3
--- /dev/null
+++ b/releasenotes/notes/ovn-add-extension-extraroute-atomic-9959973ba162db83.yaml
@@ -0,0 +1,5 @@
+---
+features:
+  - |
+    Add the extension ``extraroute-atomic`` to the ML2/OVN router plugin. This
+    extension does not require any specific implementation.