diff --git a/src/sentry/api/endpoints/organization_fork.py b/src/sentry/api/endpoints/organization_fork.py
index 863a0e98f16f00..4f06dd1abc0df0 100644
--- a/src/sentry/api/endpoints/organization_fork.py
+++ b/src/sentry/api/endpoints/organization_fork.py
@@ -22,7 +22,7 @@
 )
 from sentry.relocation.models.relocation import Relocation
 from sentry.relocation.tasks.process import uploading_start
-from sentry.types.cell import get_local_cell
+from sentry.types.cell import get_global_directory, get_local_cell
 from sentry.utils.db import atomic_transaction
 
 ERR_DUPLICATE_ORGANIZATION_FORK = Template(
@@ -35,12 +35,12 @@
 ERR_CANNOT_FORK_INTO_SAME_REGION = Template(
     "The organization already lives in region `$region`, so it cannot be forked into that region."
 )
-ERR_CANNOT_FORK_FROM_REGION = Template(
-    "Forking an organization from region `$region` is forbidden."
+ERR_CANNOT_FORK_FROM_LOCALITY = Template(
+    "Forking an organization from locality `$locality` is forbidden."
 )
 
-# For legal reasons, there are certain regions from which forking is disallowed.
-CANNOT_FORK_FROM_REGION = {"de"}
+# For legal reasons, there are certain localities from which forking is disallowed.
+CANNOT_FORK_FROM_LOCALITY = {"de"}
 
 logger = logging.getLogger(__name__)
 
@@ -99,23 +99,29 @@ def post(self, request: Request, organization_id_or_slug) -> Response:
                 status=status.HTTP_400_BAD_REQUEST,
             )
 
-        # Figure out which region the organization being forked lives in.
-        requesting_region_name = get_local_cell().name
-        replying_region_name = org_mapping.cell_name
-        if replying_region_name in CANNOT_FORK_FROM_REGION:
+        # Figure out which cell the organization being forked lives in.
+        requesting_cell_name = get_local_cell().name
+        replying_cell_name = org_mapping.cell_name
+
+        # Resolve the locality for the exporting cell. In environments without locality
+        # config (e.g. monolith, tests), falls back to the cell name.
+        replying_locality = get_global_directory().get_locality_for_cell(replying_cell_name)
+        replying_locality_name = replying_locality.name if replying_locality else replying_cell_name
+
+        if replying_locality_name in CANNOT_FORK_FROM_LOCALITY:
             return Response(
                 {
-                    "detail": ERR_CANNOT_FORK_FROM_REGION.substitute(
-                        region=replying_region_name,
+                    "detail": ERR_CANNOT_FORK_FROM_LOCALITY.substitute(
+                        locality=replying_locality_name,
                     )
                 },
                 status=status.HTTP_403_FORBIDDEN,
             )
-        if replying_region_name == requesting_region_name:
+        if replying_cell_name == requesting_cell_name:
             return Response(
                 {
                     "detail": ERR_CANNOT_FORK_INTO_SAME_REGION.substitute(
-                        region=requesting_region_name,
+                        region=requesting_cell_name,
                     )
                 },
                 status=status.HTTP_400_BAD_REQUEST,
@@ -164,7 +170,7 @@ def post(self, request: Request, organization_id_or_slug) -> Response:
         # When we received this back (via RPC call), we'll be able to continue with the usual
         # relocation flow, picking up from the `uploading_complete` task.
         uploading_start.apply_async(
-            args=[new_relocation.uuid, replying_region_name, org_mapping.slug]
+            args=[new_relocation.uuid, replying_cell_name, org_mapping.slug]
         )
 
         try:
@@ -174,8 +180,8 @@ def post(self, request: Request, organization_id_or_slug) -> Response:
                     owner_id=owner.id,
                     uuid=str(new_relocation.uuid),
                     from_org_slug=org_mapping.slug,
-                    requesting_region_name=requesting_region_name,
-                    replying_region_name=replying_region_name,
+                    requesting_region_name=requesting_cell_name,
+                    replying_region_name=replying_cell_name,
                 )
             )
         except Exception as e:
diff --git a/tests/sentry/api/endpoints/test_organization_fork.py b/tests/sentry/api/endpoints/test_organization_fork.py
index 4115540715e9d2..a68e3e1de7c0ea 100644
--- a/tests/sentry/api/endpoints/test_organization_fork.py
+++ b/tests/sentry/api/endpoints/test_organization_fork.py
@@ -3,7 +3,7 @@
 
 from sentry.analytics.events.relocation_forked import RelocationForkedEvent
 from sentry.api.endpoints.organization_fork import (
-    ERR_CANNOT_FORK_FROM_REGION,
+    ERR_CANNOT_FORK_FROM_LOCALITY,
     ERR_CANNOT_FORK_INTO_SAME_REGION,
     ERR_DUPLICATE_ORGANIZATION_FORK,
     ERR_ORGANIZATION_INACTIVE,
@@ -394,7 +394,8 @@ def test_bad_cannot_fork_deleted_organization(
     @override_options({"relocation.enabled": True, "relocation.daily-limit.small": 1})
     @assume_test_silo_mode(SiloMode.CELL, cell_name=REQUESTING_TEST_REGION)
     @patch(
-        "sentry.api.endpoints.organization_fork.CANNOT_FORK_FROM_REGION", {EXPORTING_TEST_REGION}
+        "sentry.api.endpoints.organization_fork.CANNOT_FORK_FROM_LOCALITY",
+        {EXPORTING_TEST_REGION},
     )
     def test_bad_organization_in_forbidden_region(
         self,
@@ -408,8 +409,8 @@ def test_bad_organization_in_forbidden_region(
         response = self.get_error_response(self.existing_org.slug, status_code=403)
 
         assert response.data.get("detail") is not None
-        assert response.data.get("detail") == ERR_CANNOT_FORK_FROM_REGION.substitute(
-            region=EXPORTING_TEST_REGION,
+        assert response.data.get("detail") == ERR_CANNOT_FORK_FROM_LOCALITY.substitute(
+            locality=EXPORTING_TEST_REGION,
         )
         assert uploading_start_mock.call_count == 0
         assert analytics_record_mock.call_count == 0