diff --git a/src/wp-includes/rest-api/endpoints/class-wp-rest-block-pattern-categories-controller.php b/src/wp-includes/rest-api/endpoints/class-wp-rest-block-pattern-categories-controller.php
index 36a753416013f..0de643a37696a 100644
--- a/src/wp-includes/rest-api/endpoints/class-wp-rest-block-pattern-categories-controller.php
+++ b/src/wp-includes/rest-api/endpoints/class-wp-rest-block-pattern-categories-controller.php
@@ -76,16 +76,50 @@ public function get_items_permissions_check( $request ) {
 	 * Retrieves all block pattern categories.
 	 *
 	 * @since 6.0.0
+	 * @since 6.5.0 Includes user categories from the wp_pattern_category taxonomy in the response if `user` sepecified in the request `source` param.
 	 *
 	 * @param WP_REST_Request $request Full details about the request.
 	 * @return WP_Error|WP_REST_Response Response object on success, or WP_Error object on failure.
 	 */
 	public function get_items( $request ) {
-		$response   = array();
-		$categories = WP_Block_Pattern_Categories_Registry::get_instance()->get_all_registered();
-		foreach ( $categories as $category ) {
-			$prepared_category = $this->prepare_item_for_response( $category, $request );
-			$response[]        = $this->prepare_response_for_collection( $prepared_category );
+		$valid_query_args = array(
+			'source' => true,
+		);
+		$query_args        = array_intersect_key( $request->get_params(), $valid_query_args );
+		$response          = array();
+		$unique_categories = array();
+
+		if ( is_array( $query_args['source'] ) && in_array( 'user', $query_args['source'], true ) ) {
+			$user_categories   = get_terms(
+				array(
+					'taxonomy'   => 'wp_pattern_category',
+					'hide_empty' => false,
+				)
+			);
+			foreach ( $user_categories as $user_category ) {
+				$prepared_category   = $this->prepare_item_for_response(
+					array(
+						'name'        => $user_category->slug,
+						'label'       => $user_category->name,
+						'description' => $user_category->description,
+						'id'          => $user_category->term_id,
+					),
+					$request
+				);
+				$response[]          = $this->prepare_response_for_collection( $prepared_category );
+				$unique_categories[] = $user_category->name;
+			}
+		}
+
+		if ( ! isset( $query_args['source'] ) || in_array( 'core', $query_args['source'], true ) ) {
+			$categories        = WP_Block_Pattern_Categories_Registry::get_instance()->get_all_registered();
+			foreach ( $categories as $category ) {
+				if ( in_array( $category['label'], $unique_categories, true ) ) {
+					continue;
+				}
+				$prepared_category = $this->prepare_item_for_response( $category, $request );
+				$response[]        = $this->prepare_response_for_collection( $prepared_category );
+			}
 		}
 
 		return rest_ensure_response( $response );
@@ -95,6 +129,7 @@ public function get_items( $request ) {
 	 * Prepare a raw block pattern category before it gets output in a REST API response.
 	 *
 	 * @since 6.0.0
+	 * @since 6.5 Added `id` field for identifying user categories
 	 *
 	 * @param array           $item    Raw category as registered, before any changes.
 	 * @param WP_REST_Request $request Request object.
@@ -110,6 +145,11 @@ public function prepare_item_for_response( $item, $request ) {
 			}
 		}
 
+		// For backwards compatibility we only want to include the id if the field is explicitly requested.
+		if ( rest_is_field_included( 'id', $fields ) && isset( $item['id'] ) ) {
+			$data['id'] = $item['id'];
+		}
+
 		$context = ! empty( $request['context'] ) ? $request['context'] : 'view';
 		$data    = $this->add_additional_fields_to_object( $data, $request );
 		$data    = $this->filter_response_by_context( $data, $context );
@@ -152,6 +192,12 @@ public function get_item_schema() {
 					'readonly'    => true,
 					'context'     => array( 'view', 'edit', 'embed' ),
 				),
+				'id'          => array(
+					'description' => __( 'An optional category id, currently used to provide id for user wp_pattern_category terms' ),
+					'type'        => 'number',
+					'readonly'    => true,
+					'context'     => array( 'view', 'edit', 'embed' ),
+				),
 			),
 		);
 
@@ -159,4 +205,32 @@ public function get_item_schema() {
 
 		return $this->add_additional_fields_schema( $this->schema );
 	}
+
+	/**
+	 * Retrieves the search parameters for the block pattern categories.
+	 *
+	 * @since 6.5.0 Added source param to request.
+	 *
+	 * @return array Collection parameters.
+	 */
+	public function get_collection_params() {
+		$query_params = parent::get_collection_params();
+
+		$query_params['source'] = array(
+			'description' => __( 'Limit result set to specific sources, `core` and/or `user`' ),
+			'type'        => 'array',
+			'items'       => array(
+				'type' => 'string',
+			),
+		);
+
+		/**
+		 * Filter collection parameters for the block pattern categories controller.
+		 *
+		 * @since 5.8.0
+		 *
+		 * @param array $query_params JSON Schema-formatted collection parameters.
+		 */
+		return apply_filters( 'rest_pattern_directory_collection_params', $query_params );
+	}
 }