diff --git a/backport-changelog/6.8/7596.md b/backport-changelog/6.8/7596.md
new file mode 100644
index 00000000000000..2644b1ff947183
--- /dev/null
+++ b/backport-changelog/6.8/7596.md
@@ -0,0 +1,3 @@
+https://github.com/WordPress/wordpress-develop/pull/7596
+
+* https://github.com/WordPress/gutenberg/pull/66155
diff --git a/lib/class-wp-theme-json-resolver-gutenberg.php b/lib/class-wp-theme-json-resolver-gutenberg.php
index 2231cb0f11538f..5c6c8872bbfe36 100644
--- a/lib/class-wp-theme-json-resolver-gutenberg.php
+++ b/lib/class-wp-theme-json-resolver-gutenberg.php
@@ -91,6 +91,14 @@ class WP_Theme_JSON_Resolver_Gutenberg {
 	 */
 	protected static $theme_json_file_cache = array();
 
+	/**
+	 * Cache for resolved files per theme.
+	 *
+	 * @since 6.8.0
+	 * @var array
+	 */
+	protected static $resolved_theme_uris_cache = array();
+
 	/**
 	 * Processes a file that adheres to the theme.json schema
 	 * and returns an array with its contents, or a void array if none found.
@@ -696,20 +704,22 @@ protected static function get_file_path_from_theme( $file_name, $template = fals
 	 *              and `$i18n_schema` variables to reset.
 	 * @since 6.1.0 Added the `$blocks` and `$blocks_cache` variables
 	 *              to reset.
+	 * @since 6.8.0 Added the `$resolved_theme_uris_cache` variable to reset.
 	 */
 	public static function clean_cached_data() {
-		static::$core                     = null;
-		static::$blocks                   = null;
-		static::$blocks_cache             = array(
+		static::$core                      = null;
+		static::$blocks                    = null;
+		static::$blocks_cache              = array(
 			'core'   => array(),
 			'blocks' => array(),
 			'theme'  => array(),
 			'user'   => array(),
 		);
-		static::$theme                    = null;
-		static::$user                     = null;
-		static::$user_custom_post_type_id = null;
-		static::$i18n_schema              = null;
+		static::$theme                     = null;
+		static::$user                      = null;
+		static::$user_custom_post_type_id  = null;
+		static::$i18n_schema               = null;
+		static::$resolved_theme_uris_cache = array();
 	}
 
 	/**
@@ -839,6 +849,7 @@ public static function get_style_variations_from_directory( $directory, $scope =
 	 *
 	 * @since 6.6.0
 	 * @since 6.7.0 Added support for resolving block styles.
+	 * @since 6.8.0 Added caching for resolved theme URIs.
 	 *
 	 * @param WP_Theme_JSON_Gutenberg $theme_json A theme json instance.
 	 * @return array An array of resolved paths.
@@ -850,7 +861,12 @@ public static function get_resolved_theme_uris( $theme_json ) {
 			return $resolved_theme_uris;
 		}
 
-		$theme_json_data = $theme_json->get_raw_data();
+		$theme_json_data               = $theme_json->get_raw_data();
+		$resolved_theme_uris_cache_key = md5( wp_json_encode( $theme_json_data ) );
+
+		if ( ! empty( static::$resolved_theme_uris_cache[ $resolved_theme_uris_cache_key ] ) ) {
+			return static::$resolved_theme_uris_cache[ $resolved_theme_uris_cache_key ];
+		}
 
 		// Using the same file convention when registering web fonts. See: WP_Font_Face_Resolver:: to_theme_file_uri.
 		$placeholder = 'file:./';
@@ -901,7 +917,7 @@ public static function get_resolved_theme_uris( $theme_json ) {
 				}
 			}
 		}
-
+		static::$resolved_theme_uris_cache[ $resolved_theme_uris_cache_key ] = $resolved_theme_uris;
 		return $resolved_theme_uris;
 	}
 
diff --git a/phpunit/class-wp-theme-json-resolver-test.php b/phpunit/class-wp-theme-json-resolver-test.php
index d2339f2496290c..bed1a171263f4b 100644
--- a/phpunit/class-wp-theme-json-resolver-test.php
+++ b/phpunit/class-wp-theme-json-resolver-test.php
@@ -31,6 +31,20 @@ class WP_Theme_JSON_Resolver_Gutenberg_Test extends WP_UnitTestCase {
 	 */
 	private static $property_blocks_cache_orig_value;
 
+	/**
+	 * WP_Theme_JSON_Resolver_Gutenberg::$resolved_theme_uris_cache property.
+	 *
+	 * @var ReflectionProperty
+	 */
+	private static $property_resolved_theme_uris_cache;
+
+	/**
+	 * Original value of the WP_Theme_JSON_Resolver_Gutenberg::$resolved_theme_uris_cache property.
+	 *
+	 * @var array
+	 */
+	private static $property_resolved_theme_uris_cache_orig_value;
+
 	/**
 	 * WP_Theme_JSON_Resolver_Gutenberg::$core property.
 	 *
@@ -81,11 +95,16 @@ public static function set_up_before_class() {
 		static::$property_core = new ReflectionProperty( WP_Theme_JSON_Resolver_Gutenberg::class, 'core' );
 		static::$property_core->setAccessible( true );
 		static::$property_core_orig_value = static::$property_core->getValue();
+
+		static::$property_resolved_theme_uris_cache = new ReflectionProperty( WP_Theme_JSON_Resolver_Gutenberg::class, 'resolved_theme_uris_cache' );
+		static::$property_resolved_theme_uris_cache->setAccessible( true );
+		static::$property_resolved_theme_uris_cache_orig_value = static::$property_resolved_theme_uris_cache->getValue();
 	}
 
 	public static function tear_down_after_class() {
 		static::$property_blocks_cache->setValue( null, static::$property_blocks_cache_orig_value );
 		static::$property_core->setValue( null, static::$property_core_orig_value );
+		static::$property_resolved_theme_uris_cache->setValue( null, static::$property_resolved_theme_uris_cache_orig_value );
 		parent::tear_down_after_class();
 	}
 
@@ -1347,7 +1366,12 @@ public function test_get_resolved_theme_uris() {
 		$actual = WP_Theme_JSON_Resolver_Gutenberg::get_resolved_theme_uris( $theme_json );
 		remove_filter( 'theme_file_uri', $filter_theme_file_uri_callback );
 
-		$this->assertSame( $expected_data, $actual );
+		$this->assertSame( $expected_data, $actual, 'Resolved theme uris do not match.' );
+
+		// Test that resolved theme uris are cached.
+		$cache_key           = md5( wp_json_encode( $theme_json->get_raw_data() ) );
+		$expected_cache_data = array( "$cache_key" => $actual );
+		$this->assertSame( $expected_cache_data, static::$property_resolved_theme_uris_cache->getValue(), 'Resolved theme uris cache data does not match.' );
 	}
 
 	/**