The Wicked and Frozen star will guide the finalists through a Disney-themed night.
Tony winner Idina Menzel, who will join Tony nominee Josh Groban for a concert tour this fall, will be a guest mentor on the April 29 broadcast of ABC's American Idol.
The Broadway favorite, who voiced the role of Elsa in the hit Disney film Frozen, will guide the top 10 finalists through a Disney-themed night, according to Variety. Whether Menzel will perform her Frozen anthem, "Let It Go," has not been announced.
The current reboot of American Idol features judges Luke Bryan, Katy Perry, and Lionel Richie.