diff --git a/doc/source/cli/data/glance.csv b/doc/source/cli/data/glance.csv
index c248904fe1..61cd6c1e5f 100644
--- a/doc/source/cli/data/glance.csv
+++ b/doc/source/cli/data/glance.csv
@@ -26,7 +26,7 @@ md-namespace-create,image metadef namespace create,Create a new metadata definit
 md-namespace-delete,image metadef namespace delete,Delete specified metadata definitions namespace with its contents.
 md-namespace-import,,Import a metadata definitions namespace from file or standard input.
 md-namespace-list,image metadef namespace list,List metadata definitions namespaces.
-md-namespace-objects-delete,,Delete all metadata definitions objects inside a specific namespace.
+md-namespace-objects-delete,image metadef object delete,Delete all metadata definitions objects inside a specific namespace.
 md-namespace-properties-delete,,Delete all metadata definitions property inside a specific namespace.
 md-namespace-resource-type-list,image metadef resource type association list,List resource types associated to specific namespace.
 md-namespace-show,image metadef namespace show,Describe a specific metadata definitions namespace.
diff --git a/openstackclient/image/v2/metadef_objects.py b/openstackclient/image/v2/metadef_objects.py
index 04c0fa55f1..09fc249cbe 100644
--- a/openstackclient/image/v2/metadef_objects.py
+++ b/openstackclient/image/v2/metadef_objects.py
@@ -123,8 +123,11 @@ class DeleteMetadefObject(command.Command):
         parser.add_argument(
             "objects",
             metavar="<object>",
-            nargs="+",
-            help=_("Metadef object(s) to delete (name)"),
+            nargs="*",
+            help=_(
+                "Metadef object(s) to delete (name) "
+                "(omit this argument to delete all objects in the namespace)"
+            ),
         )
         return parser
 
@@ -133,6 +136,9 @@ class DeleteMetadefObject(command.Command):
 
         namespace = parsed_args.namespace
 
+        if not parsed_args.objects:
+            return image_client.delete_all_metadef_objects(namespace)
+
         result = 0
         for obj in parsed_args.objects:
             try:
diff --git a/openstackclient/tests/unit/image/v2/test_metadef_objects.py b/openstackclient/tests/unit/image/v2/test_metadef_objects.py
index 4996060d9d..6306e23eb1 100644
--- a/openstackclient/tests/unit/image/v2/test_metadef_objects.py
+++ b/openstackclient/tests/unit/image/v2/test_metadef_objects.py
@@ -113,6 +113,7 @@ class TestMetadefObjectDelete(fakes.TestImagev2):
         super().setUp()
 
         self.image_client.delete_metadef_object.return_value = None
+        self.image_client.delete_all_metadef_objects.return_value = None
         self.cmd = metadef_objects.DeleteMetadefObject(self.app, None)
 
     def test_object_delete(self):
@@ -126,8 +127,29 @@ class TestMetadefObjectDelete(fakes.TestImagev2):
 
         result = self.cmd.take_action(parsed_args)
 
+        self.image_client.delete_metadef_object.assert_called_once_with(
+            self.image_client.get_metadef_object(),
+            self._metadef_namespace.namespace,
+        )
+        self.image_client.delete_all_metadef_objects.assert_not_called()
         self.assertIsNone(result)
 
+    def test_object_delete_all(self):
+        arglist = [
+            self._metadef_namespace.namespace,
+        ]
+
+        verifylist = []
+        parsed_args = self.check_parser(self.cmd, arglist, verifylist)
+
+        result = self.cmd.take_action(parsed_args)
+
+        self.assertIsNone(result)
+        self.image_client.delete_all_metadef_objects.assert_called_with(
+            self._metadef_namespace.namespace,
+        )
+        self.image_client.delete_metadef_object.assert_not_called()
+
 
 class TestMetadefObjectList(fakes.TestImagev2):
     _metadef_namespace = fakes.create_one_metadef_namespace()
diff --git a/releasenotes/notes/add-image-metadef-namespace-object-delete-b6b2de24fc66e602.yaml b/releasenotes/notes/add-image-metadef-namespace-object-delete-b6b2de24fc66e602.yaml
new file mode 100644
index 0000000000..7861a0c7a0
--- /dev/null
+++ b/releasenotes/notes/add-image-metadef-namespace-object-delete-b6b2de24fc66e602.yaml
@@ -0,0 +1,4 @@
+---
+features:
+  - |
+    Adds operation which deletes all metadef object inside a namespace.