diff --git a/keystone/resource/core.py b/keystone/resource/core.py
index 637db0955c..e3304b7b00 100644
--- a/keystone/resource/core.py
+++ b/keystone/resource/core.py
@@ -854,32 +854,6 @@ class Manager(manager.Manager):
     def get_project_by_name(self, project_name, domain_id):
         return self.driver.get_project_by_name(project_name, domain_id)
 
-    def ensure_default_domain_exists(self):
-        """Create the default domain if it doesn't exist.
-
-        This is only used for the v2 API and can go away when V2 does.
-
-        """
-        try:
-            default_domain_attrs = {
-                'name': 'Default',
-                'id': CONF.identity.default_domain_id,
-                'description': 'Domain created automatically to support V2.0 '
-                               'operations.',
-            }
-            self.create_domain(CONF.identity.default_domain_id,
-                               default_domain_attrs)
-            LOG.warning(
-                'The default domain was created automatically to contain V2 '
-                'resources. This is deprecated in the M release and will not '
-                'be supported in the O release. Create the default domain '
-                'manually or use the keystone-manage bootstrap command.')
-        except exception.Conflict:
-            LOG.debug('The default domain already exists.')
-        except Exception:
-            LOG.error('Failed to create the default domain.')
-            raise
-
     def _require_matching_domain_id(self, new_ref, orig_ref):
         """Ensure the current domain ID matches the reference one, if any.
 
diff --git a/keystone/tests/unit/resource/test_core.py b/keystone/tests/unit/resource/test_core.py
index 11a4f8ec30..07ad8fb5db 100644
--- a/keystone/tests/unit/resource/test_core.py
+++ b/keystone/tests/unit/resource/test_core.py
@@ -13,7 +13,6 @@
 import copy
 import uuid
 
-import fixtures
 import mock
 from oslo_config import cfg
 from testtools import matchers
@@ -34,68 +33,6 @@ class TestResourceManagerNoFixtures(unit.SQLDriverOverrides, unit.TestCase):
         self.useFixture(database.Database())
         self.load_backends()
 
-    def test_ensure_default_domain_exists(self):
-        # When there's no default domain, ensure_default_domain_exists creates
-        # it.
-
-        # First make sure there's no default domain.
-        self.assertRaises(
-            exception.DomainNotFound,
-            self.resource_api.get_domain, CONF.identity.default_domain_id)
-
-        self.resource_api.ensure_default_domain_exists()
-        default_domain = self.resource_api.get_domain(
-            CONF.identity.default_domain_id)
-
-        expected_domain = {
-            'id': CONF.identity.default_domain_id,
-            'name': 'Default',
-            'enabled': True,
-            'description': 'Domain created automatically to support V2.0 '
-                           'operations.',
-            'tags': []
-        }
-        self.assertEqual(expected_domain, default_domain)
-
-    def test_ensure_default_domain_exists_already_exists(self):
-        # When there's already a default domain, ensure_default_domain_exists
-        # doesn't do anything.
-
-        name = uuid.uuid4().hex
-        description = uuid.uuid4().hex
-        domain_attrs = {
-            'id': CONF.identity.default_domain_id,
-            'name': name,
-            'description': description,
-        }
-        self.resource_api.create_domain(CONF.identity.default_domain_id,
-                                        domain_attrs)
-
-        self.resource_api.ensure_default_domain_exists()
-
-        default_domain = self.resource_api.get_domain(
-            CONF.identity.default_domain_id)
-
-        expected_domain = {
-            'id': CONF.identity.default_domain_id,
-            'name': name,
-            'enabled': True,
-            'description': description,
-            'tags': []
-        }
-
-        self.assertEqual(expected_domain, default_domain)
-
-    def test_ensure_default_domain_exists_fails(self):
-        # When there's an unexpected exception creating domain it's passed on.
-
-        self.useFixture(fixtures.MockPatchObject(
-            self.resource_api, 'create_domain',
-            side_effect=exception.UnexpectedError))
-
-        self.assertRaises(exception.UnexpectedError,
-                          self.resource_api.ensure_default_domain_exists)
-
     def test_update_project_name_conflict(self):
         name = uuid.uuid4().hex
         description = uuid.uuid4().hex