Remove Related Products in WooCommerce

WooCommerce displays related products at the bottom of the product page by default. To remove them, add the following code to your functions.php file. For more on WooCommerce hooks.

remove_action( 'woocommerce_after_single_product_summary', 'woocommerce_output_related_products', 20 );

If you only want to change the number of related products displayed instead of removing them entirely:

add_filter( 'woocommerce_output_related_products_args', function( $args ) {
	$args['posts_per_page'] = 3;
	$args['columns'] = 3;
	return $args;
} );