diff --git a/openstackclient/common/quota.py b/openstackclient/common/quota.py
index d412e05cfd..abbbe3cdb0 100644
--- a/openstackclient/common/quota.py
+++ b/openstackclient/common/quota.py
@@ -461,10 +461,15 @@ class SetQuota(common.NetDetectionMixin, command.Command):
         parser.add_argument(
             'project',
             metavar='<project/class>',
-            help=_('Set quotas for this project or class (name or ID)'),
+            nargs='?',
+            help=_(
+                'Set quotas for this project or class (name or ID) '
+                '(defaults to current project)'
+            ),
         )
         # TODO(stephenfin): Remove in OSC 8.0
-        parser.add_argument(
+        type_group = parser.add_mutually_exclusive_group()
+        type_group.add_argument(
             '--class',
             dest='quota_class',
             action='store_true',
@@ -476,6 +481,13 @@ class SetQuota(common.NetDetectionMixin, command.Command):
                 '(compute and volume only)'
             ),
         )
+        type_group.add_argument(
+            '--default',
+            dest='default',
+            action='store_true',
+            default=False,
+            help=_('Set default quotas for <project>'),
+        )
         for k, v, h in self._build_options_list():
             parser.add_argument(
                 '--%s' % v,
@@ -529,13 +541,13 @@ class SetQuota(common.NetDetectionMixin, command.Command):
                 "never fully implemented and the compute and volume services "
                 "only support a single 'default' quota class while the "
                 "network service does not support quota classes at all. "
-                "Please use 'openstack quota show --default' instead."
+                "Please use 'openstack quota set --default' instead."
             )
             self.log.warning(msg)
 
-        identity_client = self.app.client_manager.identity
         compute_client = self.app.client_manager.compute
         volume_client = self.app.client_manager.volume
+
         compute_kwargs = {}
         for k, v in COMPUTE_QUOTAS.items():
             value = getattr(parsed_args, k, None)
@@ -581,15 +593,15 @@ class SetQuota(common.NetDetectionMixin, command.Command):
                 if value is not None:
                     compute_kwargs[k] = value
 
-        if parsed_args.quota_class:
+        if parsed_args.quota_class or parsed_args.default:
             if compute_kwargs:
                 compute_client.quota_classes.update(
-                    parsed_args.project,
+                    parsed_args.project or 'default',
                     **compute_kwargs,
                 )
             if volume_kwargs:
                 volume_client.quota_classes.update(
-                    parsed_args.project,
+                    parsed_args.project or 'default',
                     **volume_kwargs,
                 )
             if network_kwargs:
@@ -600,10 +612,8 @@ class SetQuota(common.NetDetectionMixin, command.Command):
 
             return
 
-        project = utils.find_resource(
-            identity_client.projects,
-            parsed_args.project,
-        ).id
+        project_info = get_project(self.app, parsed_args.project)
+        project = project_info['id']
 
         if compute_kwargs:
             compute_client.quotas.update(project, **compute_kwargs)
diff --git a/openstackclient/tests/unit/common/test_quota.py b/openstackclient/tests/unit/common/test_quota.py
index f18e917b2b..78c84e163c 100644
--- a/openstackclient/tests/unit/common/test_quota.py
+++ b/openstackclient/tests/unit/common/test_quota.py
@@ -788,6 +788,89 @@ class TestQuotaSet(TestQuota):
         self.assertNotCalled(self.network_client.update_quota)
         self.assertIsNone(result)
 
+    def test_quota_set_default(self):
+        arglist = [
+            '--injected-files',
+            str(compute_fakes.injected_file_num),
+            '--injected-file-size',
+            str(compute_fakes.injected_file_size_num),
+            '--injected-path-size',
+            str(compute_fakes.injected_path_size_num),
+            '--key-pairs',
+            str(compute_fakes.key_pair_num),
+            '--cores',
+            str(compute_fakes.core_num),
+            '--ram',
+            str(compute_fakes.ram_num),
+            '--instances',
+            str(compute_fakes.instance_num),
+            '--properties',
+            str(compute_fakes.property_num),
+            '--server-groups',
+            str(compute_fakes.servgroup_num),
+            '--server-group-members',
+            str(compute_fakes.servgroup_members_num),
+            '--gigabytes',
+            str(compute_fakes.floating_ip_num),
+            '--snapshots',
+            str(compute_fakes.fix_ip_num),
+            '--volumes',
+            str(volume_fakes.QUOTA['volumes']),
+            '--network',
+            str(network_fakes.QUOTA['network']),
+            '--default',
+        ]
+        verifylist = [
+            ('injected_files', compute_fakes.injected_file_num),
+            (
+                'injected_file_content_bytes',
+                compute_fakes.injected_file_size_num,
+            ),
+            ('injected_file_path_bytes', compute_fakes.injected_path_size_num),
+            ('key_pairs', compute_fakes.key_pair_num),
+            ('cores', compute_fakes.core_num),
+            ('ram', compute_fakes.ram_num),
+            ('instances', compute_fakes.instance_num),
+            ('metadata_items', compute_fakes.property_num),
+            ('server_groups', compute_fakes.servgroup_num),
+            ('server_group_members', compute_fakes.servgroup_members_num),
+            ('gigabytes', compute_fakes.floating_ip_num),
+            ('snapshots', compute_fakes.fix_ip_num),
+            ('volumes', volume_fakes.QUOTA['volumes']),
+            ('network', network_fakes.QUOTA['network']),
+            ('default', True),
+        ]
+        parsed_args = self.check_parser(self.cmd, arglist, verifylist)
+
+        result = self.cmd.take_action(parsed_args)
+
+        kwargs_compute = {
+            'injected_files': compute_fakes.injected_file_num,
+            'injected_file_content_bytes': compute_fakes.injected_file_size_num,  # noqa: E501
+            'injected_file_path_bytes': compute_fakes.injected_path_size_num,
+            'key_pairs': compute_fakes.key_pair_num,
+            'cores': compute_fakes.core_num,
+            'ram': compute_fakes.ram_num,
+            'instances': compute_fakes.instance_num,
+            'metadata_items': compute_fakes.property_num,
+            'server_groups': compute_fakes.servgroup_num,
+            'server_group_members': compute_fakes.servgroup_members_num,
+        }
+        kwargs_volume = {
+            'gigabytes': compute_fakes.floating_ip_num,
+            'snapshots': compute_fakes.fix_ip_num,
+            'volumes': volume_fakes.QUOTA['volumes'],
+        }
+
+        self.compute_quotas_class_mock.update.assert_called_with(
+            'default', **kwargs_compute
+        )
+        self.volume_quotas_class_mock.update.assert_called_with(
+            'default', **kwargs_volume
+        )
+        self.assertNotCalled(self.network_client.update_quota)
+        self.assertIsNone(result)
+
     def test_quota_set_with_force(self):
         arglist = [
             '--cores',
diff --git a/releasenotes/notes/quota-set-default-option-bc26d37dc150533b.yaml b/releasenotes/notes/quota-set-default-option-bc26d37dc150533b.yaml
new file mode 100644
index 0000000000..d3ba34d652
--- /dev/null
+++ b/releasenotes/notes/quota-set-default-option-bc26d37dc150533b.yaml
@@ -0,0 +1,7 @@
+---
+features:
+  - |
+    The ``quota set`` command now supports a ``--default`` option. When
+    provided, this will allow you to set quotas for the default quota class
+    which is the only quota class supported by the Compute and Block Storage
+    services. This replaces the deprecated ``quota set --class`` option.