diff --git a/lib/compat/wordpress-6.5/class-gutenberg-rest-edit-site-export-controller-6-5.php b/lib/compat/wordpress-6.5/class-gutenberg-rest-edit-site-export-controller-6-5.php
new file mode 100644
index 0000000000000..788dc61d1d440
--- /dev/null
+++ b/lib/compat/wordpress-6.5/class-gutenberg-rest-edit-site-export-controller-6-5.php
@@ -0,0 +1,45 @@
+<?php
+/**
+ * REST API: Gutenberg_REST_Edit_Site_Export_Controller class
+ *
+ * @package    Gutenberg
+ * @subpackage REST_API
+ */
+
+/**
+ * Core class used to access block patterns via the REST API.
+ *
+ * @since 6.4.0
+ *
+ * @see WP_REST_Controller
+ */
+class Gutenberg_REST_Edit_Site_Export_Controller_6_5 extends WP_REST_Edit_Site_Export_Controller {
+	/**
+	 * Output a ZIP file with an export of the current templates
+	 * and template parts from the site editor, and close the connection.
+	 *
+	 * @since 5.9.0
+	 * @since 6.5.0 Use WP_Theme_Export class to generate theme zip file.
+	 *
+	 * @return WP_Error|void
+	 */
+	public function export() {
+		// Generate the export file.
+		$filename = WP_Theme_Export::generate_theme_export();
+
+		if ( is_wp_error( $filename ) ) {
+			$filename->add_data( array( 'status' => 500 ) );
+
+			return $filename;
+		}
+
+		$theme_name = basename( get_stylesheet() );
+		header( 'Content-Type: application/zip' );
+		header( 'Content-Disposition: attachment; filename=' . $theme_name . '.zip' );
+		header( 'Content-Length: ' . filesize( $filename ) );
+		flush();
+		readfile( $filename );
+		unlink( $filename );
+		exit;
+	}
+}
diff --git a/lib/compat/wordpress-6.5/rest-api.php b/lib/compat/wordpress-6.5/rest-api.php
index 12d789fb58b86..3f17c702fe940 100644
--- a/lib/compat/wordpress-6.5/rest-api.php
+++ b/lib/compat/wordpress-6.5/rest-api.php
@@ -10,6 +10,16 @@
 	die( 'Silence is golden.' );
 }
 
+/**
+ * Registers the Edit Site Export REST API routes.
+ */
+function gutenberg_register_edit_site_export_endpoints() {
+	$edit_site_export_controller = new Gutenberg_REST_Edit_Site_Export_Controller_6_5();
+	$edit_site_export_controller->register_routes();
+}
+
+add_action( 'rest_api_init', 'gutenberg_register_edit_site_export_endpoints' );
+
 /**
  * Registers the Global Styles Revisions REST API routes.
  */
diff --git a/lib/experimental/theme-export/class-wp-theme-export.php b/lib/experimental/theme-export/class-wp-theme-export.php
new file mode 100644
index 0000000000000..1df86c6407d1f
--- /dev/null
+++ b/lib/experimental/theme-export/class-wp-theme-export.php
@@ -0,0 +1,123 @@
+<?php
+/**
+ * WP_Theme_Export class
+ *
+ * @package   WordPress
+ * @since     6.5.0
+ */
+
+if ( class_exists( 'WP_Theme_Export' ) ) {
+	return;
+}
+
+/**
+ * Core class used to generate a theme export file.
+ *
+ * @since     6.5.0
+ */
+class WP_Theme_Export {
+	public function __construct() {
+		// empty.
+	}
+
+	/**
+	 * Generate the theme export file.
+	 *
+	 * @since 6.5.0
+	 */
+	public function generate_theme_export() {
+		global $wp_version;
+
+		if ( ! class_exists( 'ZipArchive' ) ) {
+			return new WP_Error( 'missing_zip_package', __( 'Zip Export not supported.', 'gutenberg' ) );
+		}
+
+		$obscura    = wp_generate_password( 12, false, false );
+		$theme_name = basename( get_stylesheet() );
+		$filename   = get_temp_dir() . $theme_name . $obscura . '.zip';
+
+		$zip = new ZipArchive();
+		if ( true !== $zip->open( $filename, ZipArchive::CREATE | ZipArchive::OVERWRITE ) ) {
+			return new WP_Error( 'unable_to_create_zip', __( 'Unable to open export file (archive) for writing.', 'gutenberg' ) );
+		}
+
+		$zip->addEmptyDir( 'templates' );
+		$zip->addEmptyDir( 'parts' );
+
+		// Get path of the theme.
+		$theme_path = wp_normalize_path( get_stylesheet_directory() );
+
+		// Create recursive directory iterator.
+		$theme_files = new RecursiveIteratorIterator(
+			new RecursiveDirectoryIterator( $theme_path ),
+			RecursiveIteratorIterator::LEAVES_ONLY
+		);
+
+		// Make a copy of the current theme.
+		foreach ( $theme_files as $file ) {
+			// Skip directories as they are added automatically.
+			if ( ! $file->isDir() ) {
+				// Get real and relative path for current file.
+				$file_path     = wp_normalize_path( $file );
+				$relative_path = substr( $file_path, strlen( $theme_path ) + 1 );
+
+				if ( ! wp_is_theme_directory_ignored( $relative_path ) ) {
+					$zip->addFile( $file_path, $relative_path );
+				}
+			}
+		}
+
+		// Load templates into the zip file.
+		$templates = get_block_templates();
+		foreach ( $templates as $template ) {
+			$template->content = traverse_and_serialize_blocks(
+				parse_blocks( $template->content ),
+				'_remove_theme_attribute_from_template_part_block'
+			);
+
+			$zip->addFromString(
+				'templates/' . $template->slug . '.html',
+				$template->content
+			);
+		}
+
+		// Load template parts into the zip file.
+		$template_parts = get_block_templates( array(), 'wp_template_part' );
+		foreach ( $template_parts as $template_part ) {
+			$zip->addFromString(
+				'parts/' . $template_part->slug . '.html',
+				$template_part->content
+			);
+		}
+
+		// Load theme.json into the zip file.
+		$tree = WP_Theme_JSON_Resolver::get_theme_data( array(), array( 'with_supports' => false ) );
+		// Merge with user data.
+		$tree->merge( WP_Theme_JSON_Resolver::get_user_data() );
+
+		$theme_json_raw = $tree->get_data();
+		// If a version is defined, add a schema.
+		if ( $theme_json_raw['version'] ) {
+			$theme_json_version = 'wp/' . substr( $wp_version, 0, 3 );
+			$schema             = array( '$schema' => 'https://schemas.wp.org/' . $theme_json_version . '/theme.json' );
+			$theme_json_raw     = array_merge( $schema, $theme_json_raw );
+		}
+
+		// Convert to a string.
+		$theme_json_encoded = wp_json_encode( $theme_json_raw, JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE );
+
+		// Replace 4 spaces with a tab.
+		$theme_json_tabbed = preg_replace( '~(?:^|\G)\h{4}~m', "\t", $theme_json_encoded );
+
+		// Add the theme.json file to the zip.
+		$zip->addFromString(
+			'theme.json',
+			$theme_json_tabbed
+		);
+
+		// Save changes to the zip file.
+		$zip->close();
+
+		return $filename;
+	}
+}
diff --git a/lib/load.php b/lib/load.php
index 1aa55f7581c27..3fdaa09844808 100644
--- a/lib/load.php
+++ b/lib/load.php
@@ -42,6 +42,7 @@ function gutenberg_is_experiment_enabled( $name ) {
 	require_once __DIR__ . '/compat/wordpress-6.4/theme-previews.php';
 
 	// WordPress 6.5 compat.
+	require_once __DIR__ . '/compat/wordpress-6.5/class-gutenberg-rest-edit-site-export-controller-6-5.php';
 	require_once __DIR__ . '/compat/wordpress-6.5/class-gutenberg-rest-global-styles-revisions-controller-6-5.php';
 	require_once __DIR__ . '/compat/wordpress-6.5/rest-api.php';
 
@@ -113,6 +114,9 @@ function gutenberg_is_experiment_enabled( $name ) {
 require __DIR__ . '/experimental/l10n.php';
 require __DIR__ . '/experimental/synchronization.php';
 
+// Theme export class.
+require __DIR__ . '/experimental/theme-export/class-wp-theme-export.php';
+
 if ( gutenberg_is_experiment_enabled( 'gutenberg-no-tinymce' ) ) {
 	require __DIR__ . '/experimental/disable-tinymce.php';
 }