The eighth season of American Idol premiered on Tuesday, January 13, 2009, and concluded on May 20, 2009. Simon Cowell, Paula Abdul, and Randy Jackson returned as judges, while Ryan Seacrest returned as host. This season introduced Kara DioGuardi as a permanent fourth judge. This was also Paula Abdul's last season as a judge. Kris Allen was announced the winner of the competition on May 20, 2009, defeating runner-up Adam Lambert after nearly 100 million votes were cast.

American Idol is an American singing competition television series created by Simon Fuller, produced by Fremantle North America and 19 Entertainment, and distributed by Fremantle North America. It aired on Fox from June 11, 2002, to April 7, 2016, for 15 seasons. It was on hiatus for two years until March 11, 2018, when a revival of the series began airing on ABC.