ABC The season finale of American Idol is going to have a bunch of incredible guest stars joining the contestants on stage! The three-hour live finale is set to air on ABC on Monday night, May 11 at 8/7c. There are three contestants remaining as we head into the finale and they'll be mentored by Grammy winner Alicia Keys, who is also set to perform on the episode. There are going to be so many more performers hitting the stage throughout the night as well. All three judges - Carrie Underwood, Lionel Richie, and Luke Bryan - are set to perform as well.