add_action( 'woocommerce_admin_order_data_after_shipping_address', 'admin_custom_row_after_order_addresses', 10, 1 );
function admin_custom_row_after_order_addresses( $order ){
    ?>
        </div><br clear="left">
        <!-- New custom section row -->
        <div class="order_data_column_wide">
            <h3><?php _e("My Custom row title"); ?></h3>
            <p><?php
                _e("Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas. Vestibulum tortor quam, feugiat vitae, ultricies eget, tempor sit amet, ante. Donec eu libero sit amet quam egestas semper. Aenean ultricies mi vitae est. Mauris placerat eleifend leo.");
            ?></p>
    <?php
}