Britney Spears is jumping on the "Gangnam Style" bandwagon.

The X Factor judge stopped by The Ellen DeGeneres Show to talk about working with Simon Cowell AND to get her groove on with the hottest dance craze!

Brit, who looks fabulous in a sexy red dress and nude heels, gets a personal lesson from Psy ... the South Korean rapper who created Gangnam Style.

The viral "Gangnam Style" music video has more than 131 million views on YouTube since it was uploaded less than two months ago. As for Psy, he's been signed by Justin Bieber's manager, Scooter Braun.

Loves it!