diff --git a/changelogs/fragments/7279.yml b/changelogs/fragments/7279.yml
new file mode 100644
index 00000000000..794bed4a448
--- /dev/null
+++ b/changelogs/fragments/7279.yml
@@ -0,0 +1,2 @@
+fix:
+- Unassign data source before deleteByWorkspace ([#7279](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/7279))
\ No newline at end of file
diff --git a/src/plugins/workspace/server/workspace_client.test.ts b/src/plugins/workspace/server/workspace_client.test.ts
index 208def26ad0..4339d938034 100644
--- a/src/plugins/workspace/server/workspace_client.test.ts
+++ b/src/plugins/workspace/server/workspace_client.test.ts
@@ -180,4 +180,20 @@ describe('#WorkspaceClient', () => {
 
     expect(mockCheckAndSetDefaultDataSource).toHaveBeenCalledWith(uiSettingsClient, ['id1'], true);
   });
+
+  it('delete# should unassign data source before deleting related saved objects', async () => {
+    const client = new WorkspaceClient(coreSetup, logger);
+    await client.setup(coreSetup);
+    client?.setSavedObjects(savedObjects);
+    client?.setUiSettings(uiSettings);
+
+    await client.delete(mockRequestDetail, mockWorkspaceId);
+
+    expect(deleteFromWorkspaces).toHaveBeenCalledWith(DATA_SOURCE_SAVED_OBJECT_TYPE, 'id1', [
+      mockWorkspaceId,
+    ]);
+    expect(deleteFromWorkspaces).toHaveBeenCalledWith(DATA_SOURCE_SAVED_OBJECT_TYPE, 'id2', [
+      mockWorkspaceId,
+    ]);
+  });
 });
diff --git a/src/plugins/workspace/server/workspace_client.ts b/src/plugins/workspace/server/workspace_client.ts
index 159136e1304..fe88436f38e 100644
--- a/src/plugins/workspace/server/workspace_client.ts
+++ b/src/plugins/workspace/server/workspace_client.ts
@@ -306,6 +306,21 @@ export class WorkspaceClient implements IWorkspaceClientImpl {
           }),
         };
       }
+
+      // When workspace is to be deleted, unassign all assigned data source before deleting saved object by workspace.
+      const selectedDataSources = await getDataSourcesList(savedObjectClient, [id]);
+      if (selectedDataSources.length > 0) {
+        const promises = [];
+        for (const dataSource of selectedDataSources) {
+          promises.push(
+            savedObjectClient.deleteFromWorkspaces(DATA_SOURCE_SAVED_OBJECT_TYPE, dataSource.id, [
+              id,
+            ])
+          );
+        }
+        await Promise.all(promises);
+      }
+
       await savedObjectClient.deleteByWorkspace(id);
       // delete workspace itself at last, deleteByWorkspace depends on the workspace to do permission check
       await savedObjectClient.delete(WORKSPACE_TYPE, id);