John Stamos will join American Idol as a guest mentor on Sunday during the Disney Night episode.

The 57-year-old actor and musician will provide guidance to the Top Nine during the season 19 episode filmed at Disney World, according to an article Tuesday by ET.

John has been a longtime Disney fan and currently stars in the Disney+ original series Big Shot.

Guest mentor: John Stamos, shown earlier this month, will join American Idol as a guest mentor on Sunday during the Disney Night episode

The Orange County native even proposed to his wife Caitlin McHugh, 34, at Disneyland in Anaheim, California in October 2017.

John recently spoke with ET about becoming a mentor to American Idol’s top contestants.

‘They said, you know, ”Could you come down and be a mentor?” I’m like, ”Mentor?!” These kids are so great I’m gonna tell them one thing, and they’re gonna go, ”Stamos, we’ve heard you sing. Stop”,’ John laughed. 

‘I think John probably said yes when he heard ”Disney”,’ Katy said. 

The judges: Lionel Richie, Katy Perry and Luke Bryan, shown earlier this month, have been serving as judges on American Idol since its reboot on ABC

She added: ‘The thing is, John and I are probably the biggest Disney fans. So he gets to go to Disney World with the kids, which is basically the greatest place on Earth, and so I’m a little jealous because they didn’t ask me. I would’ve totally done it!’.

John and Caitlin have three-year-old son William together, while Katy has eight-month-old daughter Daisy with fiance Orlando Bloom, 44.

The Full House star performed with The Beach Boys dating back to 1985 and won the 2009–10 Golden Icon Award for best actor in a musical for his performance in the Broadway revival of Bye Bye Birdie. 

Disney fan: John has been a longtime Disney fan and currently stars in the Disney+ original series Big Shot

John also had a starring role in the November 2019 musical TV special The Little Mermaid Live! on ABC.

He portrayed Chef Louis and reprised his role from the live concert event at the Hollywood Bowl.

American Idol will air Sunday on ABC. 

Cute couple: The Orange County native even proposed to his wife Caitlin McHugh, shown together in November 2018 in Los Angeles, at Disneyland in Anaheim, California in October 2017