Check out the [`wp_cookie_constants()`][1] and [`ms_cookie_constants()`][2] functions, to see available cookies. We can try this in the `wp-config.php` file: // Here we just simulate how it's done in the core define( 'COOKIEHASH', md5( 'http://example.tld' ) ); // Then we override the cookie names: define( 'USER_COOKIE', 'wpse_user_' . COOKIEHASH ); define( 'PASS_COOKIE', 'wpse_pass_' . COOKIEHASH ); define( 'AUTH_COOKIE', 'wpse_' . COOKIEHASH ); define( 'SECURE_AUTH_COOKIE', 'wpse_sec_' . COOKIEHASH ); define( 'LOGGED_IN_COOKIE', 'wpse_logged_in_' . COOKIEHASH ); define( 'TEST_COOKIE', 'wpse_test_cookie' ); or using PHP 5.6+ : // Then we override the cookie names: const USER_COOKIE = 'wpse_user_' . COOKIEHASH; const PASS_COOKIE = 'wpse_pass_' . COOKIEHASH; const AUTH_COOKIE = 'wpse_' . COOKIEHASH; const SECURE_AUTH_COOKIE = 'wpse_sec_' . COOKIEHASH; const LOGGED_IN_COOKIE = 'wpse_logged_in_' . COOKIEHASH; const TEST_COOKIE = 'wpse_test_cookie'; where we must adjust the site url `http://example.tld` to our needs. But I also wonder, as @PieterGoosen, why you need to change it. [1]: https://developer.wordpress.org/reference/functions/wp_cookie_constants/ [2]: https://developer.wordpress.org/reference/functions/ms_cookie_constants/