American Idol season 9

The ninth season of American Idol premiered on Fox on Tuesday, January 12, 2010, and concluded on Wednesday, May 26, 2010. Simon Cowell, Kara DioGuardi, and Randy Jackson returned as judges and were joined by Ellen DeGeneres, who was brought on as a replacement for Paula Abdul after a series of guest judges filled in for the auditions. Idol Gives Back returned on April 21, 2010. The top 24 semifinal format used in the fourth through seventh seasons also returned this season. Cowell, DioGuardi, and DeGeneres all left the show after this season, although only Cowell's departure was announced in advance.

Lee DeWyze, a folk rocker from Mount Prospect, Illinois, won the competition, beating out fellow folk rocker Crystal Bowersox, who was the runner-up. Multiple contestants from this season were signed to record deals including DeWyze, Bowersox, Casey James, Michael Lynche, and Siobhan Magnus. Several contestants who did not even make it to the semifinals eventually had a breakthrough in the music industry, including Tori Kelly, Lauren Daigle, and Tasha Layton.