diff --git a/lib/compat/wordpress-6.1/class-wp-theme-json-resolver-6-1.php b/lib/compat/wordpress-6.1/class-wp-theme-json-resolver-6-1.php
index f704daaffafb1d..457b5c6c2b7c3a 100644
--- a/lib/compat/wordpress-6.1/class-wp-theme-json-resolver-6-1.php
+++ b/lib/compat/wordpress-6.1/class-wp-theme-json-resolver-6-1.php
@@ -16,6 +16,83 @@
  * @access private
  */
 class WP_Theme_JSON_Resolver_6_1 extends WP_Theme_JSON_Resolver_6_0 {
+	/**
+	 * Returns the custom post type that contains the user's origin config
+	 * for the current theme or a void array if none are found.
+	 *
+	 * This can also create and return a new draft custom post type.
+	 *
+	 * @param WP_Theme $theme              The theme object.  If empty, it
+	 *                                     defaults to the current theme.
+	 * @param bool     $create_post        Optional. Whether a new custom post
+	 *                                     type should be created if none are
+	 *                                     found.  False by default.
+	 * @param array    $post_status_filter Filter Optional. custom post type by
+	 *                                     post status.  ['publish'] by default,
+	 *                                     so it only fetches published posts.
+	 * @return array Custom Post Type for the user's origin config.
+	 */
+	public static function get_user_data_from_wp_global_styles( $theme, $create_post = false, $post_status_filter = array( 'publish' ) ) {
+		if ( ! $theme instanceof WP_Theme ) {
+			$theme = wp_get_theme();
+		}
+		$user_cpt         = array();
+		$post_type_filter = 'wp_global_styles';
+		$args             = array(
+			'posts_per_page'      => 1,
+			'orderby'             => 'post_date',
+			'order'               => 'desc',
+			'post_type'           => $post_type_filter,
+			'post_status'         => $post_status_filter,
+			'tax_query'           => array(
+				array(
+					'taxonomy' => 'wp_theme',
+					'field'    => 'name',
+					'terms'    => $theme->get_stylesheet(),
+				),
+			),
+			'ignore_sticky_posts' => true,
+			'no_found_rows'       => true,
+		);
+
+		$cache_key = sprintf( 'wp_global_styles_%s', md5( serialize( $args ) ) );
+		$post_id   = (int) get_transient( $cache_key );
+		// Special case: '-1' is a results not found.
+		if ( -1 === $post_id && ! $create_post ) {
+			return $user_cpt;
+		}
+
+		if ( $post_id > 0 && in_array( get_post_status( $post_id ), (array) $post_status_filter, true ) ) {
+			return get_post( $post_id, ARRAY_A );
+		}
+
+		$gs_query     = new WP_Query();
+		$recent_posts = $gs_query->query( $args );
+		if ( count( $recent_posts ) === 1 ) {
+			$user_cpt = get_post( $recent_posts[0], ARRAY_A );
+		} elseif ( $create_post ) {
+			$cpt_post_id = wp_insert_post(
+				array(
+					'post_content' => '{"version": ' . WP_Theme_JSON_Gutenberg::LATEST_SCHEMA . ', "isGlobalStylesUserThemeJSON": true }',
+					'post_status'  => 'publish',
+					'post_title'   => __( 'Custom Styles', 'default' ),
+					'post_type'    => $post_type_filter,
+					'post_name'    => 'wp-global-styles-' . urlencode( wp_get_theme()->get_stylesheet() ),
+					'tax_input'    => array(
+						'wp_theme' => array( wp_get_theme()->get_stylesheet() ),
+					),
+				),
+				true
+			);
+			if ( ! is_wp_error( $cpt_post_id ) ) {
+				$user_cpt = get_post( $cpt_post_id, ARRAY_A );
+			}
+		}
+		$cache_expiration = $user_cpt ? DAY_IN_SECONDS : HOUR_IN_SECONDS;
+		set_transient( $cache_key, $user_cpt ? $user_cpt['ID'] : -1, $cache_expiration );
+
+		return $user_cpt;
+	}
 
 	/**
 	 * Container for data coming from core.
diff --git a/phpunit/class-wp-theme-json-resolver-test.php b/phpunit/class-wp-theme-json-resolver-test.php
index 489b2b72c91c44..109e0d787d92f0 100644
--- a/phpunit/class-wp-theme-json-resolver-test.php
+++ b/phpunit/class-wp-theme-json-resolver-test.php
@@ -268,6 +268,9 @@ function test_merges_child_theme_json_into_parent_theme_json() {
 		);
 	}
 
+	/**
+	 * @covers WP_Theme_JSON_Resolver_Gutenberg::get_user_data_from_wp_global_styles
+	 */
 	function test_get_user_data_from_wp_global_styles_does_not_use_uncached_queries() {
 		add_filter( 'query', array( $this, 'filter_db_query' ) );
 		$query_count = count( $this->queries );
@@ -276,7 +279,7 @@ function test_get_user_data_from_wp_global_styles_does_not_use_uncached_queries(
 			WP_Theme_JSON_Resolver_Gutenberg::clean_cached_data();
 		}
 		$query_count = count( $this->queries ) - $query_count;
-		$this->assertEquals( 1, $query_count, 'Only one SQL query should be peformed for multiple invocations of WP_Theme_JSON_Resolver_Gutenberg::get_user_data_from_wp_global_styles()' );
+		$this->assertEquals( 0, $query_count, 'Unexpected SQL queries detected for the wp_global_style post type' );
 
 		$user_cpt = WP_Theme_JSON_Resolver_Gutenberg::get_user_data_from_wp_global_styles( wp_get_theme() );
 		$this->assertEmpty( $user_cpt );
@@ -286,11 +289,55 @@ function test_get_user_data_from_wp_global_styles_does_not_use_uncached_queries(
 
 		$query_count = count( $this->queries );
 		for ( $i = 0; $i < 3; $i++ ) {
-			WP_Theme_JSON_Resolver_Gutenberg::get_user_data_from_wp_global_styles( wp_get_theme() );
+			$new_user_cpt = WP_Theme_JSON_Resolver_Gutenberg::get_user_data_from_wp_global_styles( wp_get_theme() );
 			WP_Theme_JSON_Resolver_Gutenberg::clean_cached_data();
+			$this->assertSameSets( $user_cpt, $new_user_cpt );
 		}
 		$query_count = count( $this->queries ) - $query_count;
 		$this->assertEquals( 0, $query_count, 'Unexpected SQL queries detected for the wp_global_style post type' );
 		remove_filter( 'query', array( $this, 'filter_db_query' ) );
 	}
+
+	/**
+	 * @covers WP_Theme_JSON_Resolver_Gutenberg::get_user_data_from_wp_global_styles
+	 * @ticket 55392
+	 */
+	function test_get_user_data_from_wp_global_styles_does_exist() {
+		$post1 = WP_Theme_JSON_Resolver_Gutenberg::get_user_data_from_wp_global_styles( wp_get_theme(), true );
+		$this->assertIsArray( $post1 );
+		$this->assertArrayHasKey( 'ID', $post1 );
+		wp_delete_post( $post1['ID'], true );
+		$post2 = WP_Theme_JSON_Resolver_Gutenberg::get_user_data_from_wp_global_styles( wp_get_theme(), true );
+		$this->assertIsArray( $post2 );
+		$this->assertArrayHasKey( 'ID', $post2 );
+	}
+
+	/**
+	 * @covers WP_Theme_JSON_Resolver_Gutenberg::get_user_data_from_wp_global_styles
+	 * @ticket 55392
+	 */
+	function test_get_user_data_from_wp_global_styles_create_post() {
+		$post1 = WP_Theme_JSON_Resolver_Gutenberg::get_user_data_from_wp_global_styles( wp_get_theme( 'testing' ) );
+		$this->assertIsArray( $post1 );
+		$this->assertSameSets( array(), $post1 );
+		$post2 = WP_Theme_JSON_Resolver_Gutenberg::get_user_data_from_wp_global_styles( wp_get_theme( 'testing' ) );
+		$this->assertIsArray( $post2 );
+		$this->assertSameSets( array(), $post2 );
+		$post3 = WP_Theme_JSON_Resolver_Gutenberg::get_user_data_from_wp_global_styles( wp_get_theme( 'testing' ), true );
+		$this->assertIsArray( $post3 );
+		$this->assertArrayHasKey( 'ID', $post3 );
+	}
+
+	/**
+	 * @covers WP_Theme_JSON_Resolver_Gutenberg::get_user_data_from_wp_global_styles
+	 * @ticket 55392
+	 */
+	function test_get_user_data_from_wp_global_styles_filter_state() {
+		$post1 = WP_Theme_JSON_Resolver_Gutenberg::get_user_data_from_wp_global_styles( wp_get_theme( 'foo' ), true, array( 'publish' ) );
+		$this->assertIsArray( $post1 );
+		$this->assertArrayHasKey( 'ID', $post1 );
+		$post2 = WP_Theme_JSON_Resolver_Gutenberg::get_user_data_from_wp_global_styles( wp_get_theme( 'foo' ), false, array( 'draft' ) );
+		$this->assertIsArray( $post2 );
+		$this->assertSameSets( array(), $post2 );
+	}
 }