How do I add a Single Page Template in WordPress?

To add a single-page template, create a new template file in your active theme. In /wp-content/themes/your-theme/, add page-custom.php and include: <?php /* Template Name: Single Page Layout */ ?> at the top. Add get_header(); your markup (or the Loop), and get_footer();. Save and upload. Then open the page in WordPress admin, click the page’s Template option in the right sidebar (Page Attributes), select “Single Page Layout,” and update. For block themes, go to Appearance → Editor → Templates → Add New, design it, and assign it to the page. Use a child theme to avoid losing it on theme updates.