diff --git a/.changeset/tricky-flies-destroy.md b/.changeset/tricky-flies-destroy.md
new file mode 100644
index 0000000000..c79a4e771c
--- /dev/null
+++ b/.changeset/tricky-flies-destroy.md
@@ -0,0 +1,6 @@
+---
+'@backstage/plugin-catalog-react': patch
+'@backstage/plugin-catalog': patch
+---
+
+Added support for providing an `initiallySelectedNamspaces` which accepts an array of Namespaces to have selected by default
diff --git a/packages/app/src/App.tsx b/packages/app/src/App.tsx
index 3d8bd45e5a..04ce831d6a 100644
--- a/packages/app/src/App.tsx
+++ b/packages/app/src/App.tsx
@@ -161,7 +161,10 @@ const routes = (
     <Route path="/home" element={<HomepageCompositionRoot />}>
       {homePage}
     </Route>
-    <Route path="/catalog" element={<CatalogIndexPage />} />
+    <Route
+      path="/catalog"
+      element={<CatalogIndexPage initiallySelectedNamespaces={['default']} />}
+    />
     <Route
       path="/catalog/:namespace/:kind/:name"
       element={<CatalogEntityPage />}
diff --git a/packages/catalog-model/examples/components/different-namespace.yaml b/packages/catalog-model/examples/components/different-namespace.yaml
new file mode 100644
index 0000000000..accc5518de
--- /dev/null
+++ b/packages/catalog-model/examples/components/different-namespace.yaml
@@ -0,0 +1,10 @@
+apiVersion: backstage.io/v1alpha1
+kind: Component
+metadata:
+  name: different-namespace
+  namespace: alternative
+  description: Example of a Component in a different namespace
+spec:
+  type: service
+  lifecycle: experimental
+  owner: default/team-a
\ No newline at end of file
diff --git a/plugins/catalog-react/api-report.md b/plugins/catalog-react/api-report.md
index 39db26df74..11f35fc56d 100644
--- a/plugins/catalog-react/api-report.md
+++ b/plugins/catalog-react/api-report.md
@@ -342,7 +342,15 @@ export class EntityNamespaceFilter implements EntityFilter {
 }
 
 // @public (undocumented)
-export const EntityNamespacePicker: () => React_2.JSX.Element;
+export const EntityNamespacePicker: (
+  props: EntityNamespacePickerProps,
+) => React_2.JSX.Element;
+
+// @public
+export interface EntityNamespacePickerProps {
+  // (undocumented)
+  initiallySelectedNamespaces?: string[];
+}
 
 // @public
 export class EntityOrphanFilter implements EntityFilter {
diff --git a/plugins/catalog-react/src/components/EntityNamespacePicker/EntityNamespacePicker.test.tsx b/plugins/catalog-react/src/components/EntityNamespacePicker/EntityNamespacePicker.test.tsx
index c4b5e64c9d..762cbd2a2a 100644
--- a/plugins/catalog-react/src/components/EntityNamespacePicker/EntityNamespacePicker.test.tsx
+++ b/plugins/catalog-react/src/components/EntityNamespacePicker/EntityNamespacePicker.test.tsx
@@ -240,4 +240,25 @@ describe('<EntityNamespacePicker/>', () => {
       expect(screen.queryByText('Namespace')).not.toBeInTheDocument(),
     );
   });
+  it('renders initially selected namespaces', async () => {
+    render(
+      <TestApiProvider apis={[[catalogApiRef, mockCatalogApiRef]]}>
+        <MockEntityListContextProvider value={{}}>
+          <EntityNamespacePicker
+            initiallySelectedNamespaces={['namespace-2', 'namespace-3']}
+          />
+        </MockEntityListContextProvider>
+      </TestApiProvider>,
+    );
+    await waitFor(() =>
+      expect(screen.getByText('Namespace')).toBeInTheDocument(),
+    );
+
+    const buttons = screen
+      .getAllByRole('button')
+      .map(o => o.textContent)
+      .filter(b => b);
+
+    expect(buttons).toEqual(['namespace-2', 'namespace-3']);
+  });
 });
diff --git a/plugins/catalog-react/src/components/EntityNamespacePicker/EntityNamespacePicker.tsx b/plugins/catalog-react/src/components/EntityNamespacePicker/EntityNamespacePicker.tsx
index c6b59f9275..80ed42dfa3 100644
--- a/plugins/catalog-react/src/components/EntityNamespacePicker/EntityNamespacePicker.tsx
+++ b/plugins/catalog-react/src/components/EntityNamespacePicker/EntityNamespacePicker.tsx
@@ -32,8 +32,18 @@ const useStyles = makeStyles(
   },
 );
 
+/**
+ * Props for {@link EntityNamespacePicker}.
+ *
+ * @public
+ */
+export interface EntityNamespacePickerProps {
+  initiallySelectedNamespaces?: string[];
+}
+
 /** @public */
-export const EntityNamespacePicker = () => {
+export const EntityNamespacePicker = (props: EntityNamespacePickerProps) => {
+  const { initiallySelectedNamespaces } = props;
   const classes = useStyles();
   return (
     <EntityAutocompletePicker
@@ -42,6 +52,7 @@ export const EntityNamespacePicker = () => {
       path="metadata.namespace"
       Filter={EntityNamespaceFilter}
       InputProps={{ className: classes.input }}
+      initialSelectedOptions={initiallySelectedNamespaces}
     />
   );
 };
diff --git a/plugins/catalog-react/src/components/EntityNamespacePicker/index.ts b/plugins/catalog-react/src/components/EntityNamespacePicker/index.ts
index d08536ea2c..f0ec645e32 100644
--- a/plugins/catalog-react/src/components/EntityNamespacePicker/index.ts
+++ b/plugins/catalog-react/src/components/EntityNamespacePicker/index.ts
@@ -13,6 +13,6 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-
 export { EntityNamespacePicker } from './EntityNamespacePicker';
+export type { EntityNamespacePickerProps } from './EntityNamespacePicker';
 export type { CatalogReactEntityNamespacePickerClassKey } from './EntityNamespacePicker';
diff --git a/plugins/catalog/api-report.md b/plugins/catalog/api-report.md
index 40d90abe40..6da30f6f84 100644
--- a/plugins/catalog/api-report.md
+++ b/plugins/catalog/api-report.md
@@ -239,6 +239,8 @@ export interface DefaultCatalogPageProps {
   // (undocumented)
   initiallySelectedFilter?: UserListFilterKind;
   // (undocumented)
+  initiallySelectedNamespaces?: string[];
+  // (undocumented)
   ownerPickerMode?: EntityOwnerPickerProps['mode'];
   // (undocumented)
   pagination?:
diff --git a/plugins/catalog/src/components/CatalogPage/DefaultCatalogPage.tsx b/plugins/catalog/src/components/CatalogPage/DefaultCatalogPage.tsx
index d002552311..1b91bddf2a 100644
--- a/plugins/catalog/src/components/CatalogPage/DefaultCatalogPage.tsx
+++ b/plugins/catalog/src/components/CatalogPage/DefaultCatalogPage.tsx
@@ -97,6 +97,7 @@ export interface DefaultCatalogPageProps {
   ownerPickerMode?: EntityOwnerPickerProps['mode'];
   pagination?: boolean | { limit?: number };
   filters?: ReactNode;
+  initiallySelectedNamespaces?: string[];
 }
 
 export function DefaultCatalogPage(props: DefaultCatalogPageProps) {
@@ -110,6 +111,7 @@ export function DefaultCatalogPage(props: DefaultCatalogPageProps) {
     pagination,
     ownerPickerMode,
     filters,
+    initiallySelectedNamespaces,
   } = props;
 
   return (