Hide a Post by Displaying the 404 Error Page

Create a function which will check your condition. If the condition is met, set $wp_query->is_404 to true. Then call that function like add_action(‘template_redirect’, ‘functionName’); function functionName() { global $wp_query, $post; if (condition here) { $wp_query->is_404 = true; } } add_action(‘template_redirect’, ‘functionName’);