woogist

/**
 * Display field value on the order edition page
 **/
add_action( 'woocommerce_admin_order_data_after_billing_address', 'my_custom_checkout_field_display_admin_order_meta', 10, 1 );

function my_custom_checkout_field_display_admin_order_meta($order){
    echo '<p><strong>'.__('My Field').':</strong> ' . $order->order_custom_fields['My Field'][0] . '</p>';
}