Admin Page Languge

No guarantees, but this might work..

add_action( 'admin_init', 'init_locale_change' );
function init_locale_change() {
	add_filter( 'plugin_locale' , 'switch_admin_locale' );
}
function switch_admin_locale( $locale ) {
	$locale = 'en_US';
	return $locale;
}

Should only switch the locale on the admin side.

Hope that helps..

edit: *removed previous response*

I’ve just realised this won’t work, this will only over-ride plugin language settings, looking at the lang functions now to see if i can find an appropriate filter/hook..

edit:

Try this instead.

add_action( 'admin_init', 'init_locale_change' );
function init_locale_change() {
	add_filter( 'override_load_textdomain' , 'switch_admin_locale' );
}
function switch_admin_locale( $true_false ) {
	return true;
}

Code can be placed into your theme’s functions.php file. It’s untested (i don’t run in any other language), so let me know the results… 😉