Hide the Quantity input field for specific products in WooCommerce

You can use the following code to add some custom CSS to your page which will hide the quantity input only if the product has the hide_quantity_input meta key.

To add this, you can use the Custom Fields meta box in the product edit screen. Click “Enter New” and then enter hide_quantity_input as the name and any value you wish. When you are done click Add Custom Field.

<?php
function sv_hide_quantity_input() {
    $post_id = get_queried_object_id();

    if ( is_product() && metadata_exists( 'post', $post_id, 'hide_quantity_input' ) ) {
        ?>
            <style type="text/css">
                form.cart div.quantity {
                    display: none !important;
                }
            </style>
        <?php
    }
}
add_action( 'wp_head', 'sv_hide_quantity_input' );
?>

That’s it!