We've previously covered embedding videos, SlideShare, and SoundCloud in WordPress using oEmbed. A reader asked how to easily add Instagram support the same way. The good news: it's straightforward. This guide from WPBeginner shows you how to enable Instagram oEmbed in WordPress.
Key Update: This tutorial is no longer needed. WordPress 3.5+ includes built-in Instagram oEmbed support.
For older WordPress versions, create a blank PHP file named wpb-instagram.php. Copy the code below, save it, upload to your /wp-content/plugins/ folder, and activate the plugin via your dashboard.
Just paste the Instagram post URL on its own line in any post or page. WordPress will automatically embed the content. Simple as that.