Mariah Carey has booked her next gig: season 12 of “American Idol.”

Announcement of Carey as an “Idol” judge came Monday at Fox’s Television Critics Assn. press tour exec panel with Fox entertainment prexy Kevin Reilly, who phoned Carey while on stage.

Deal had been completed shortly hours before Reilly took the stage at the Beverly Hilton.

“This all happened really quickly,” said Carey over Reilly’s speakerphone. “I can’t wait to get started in a few months.”

Carey is the first judge to be confirmed for the upcoming “Idol” season after a judge overhaul that saw the departure of Jennifer Lopez and Steven Tyler within days of one other. Randy Jackson’s involvement in “Idol” season 12 has yet to be determined, though Reilly noted that Jackson is Carey’s co-manager and was “instrumental” in executing the judge deal with the chantoosie.

“Mariah is biggest recording artists any of these shows have ever had. Many contestants have tried to emulate her, and sung her songs,” said Reilly.

At an earlier “So You Think You Can Dance” panel, Nigel Lythgoe noted that while Lopez stated she was “99%” sure she’d be departing the “Idol” judges table, he saw hope in that remaining “1%.” Reilly quickly dispelled that notion, remarking that Lythgoe made the statement out of “human emotion” and that Lopez would not be returning.