Katy Perry, Lionel Richie replaced by ‘big time’ guest judges on ‘American Idol’

“Big time” acts will replace “American Idol” judges Katy Perry, 38, and Lionel Richie, 73, while they perform across the pond at King Charles III’s coronation.

The royal ceremony itself takes place at Westminster Abbey on Saturday, May 6, and the related celebratory concert will take place a day later on the grounds of Windsor Castle.

The top seven Season 21 “Idol” contestants also will perform on the ABC series on May 7.

Fellow judge Luke Bryan, 46, revealed the temporary switch-up to “Entertainment Tonight” over the weekend while headlining the Stagecoach festival.

“It’s big time. It’s big time, but I cannot tease,” the “Knockin’ Boots” singer told the outlet.

However, Bryan did offer one major clue about the fill-ins.

“The people that we have filling in, contestants have used their songs many, many times. A lot more than mine!”

When asked to elaborate further, he responded: “I’m already lucky to keep being a part of this show, you’re not getting me kicked off ‘Idol.’”

The Post has contacted representatives for Richie, Perry and “Idol” for comment.

Meanwhile, the “California Gurls” and “Hello” singers Perry and Richie are on the roster to perform at the king’s event, along with famed Italian tenor Andrea Bocelli, Welsh singer Sir Bryn Terfel and the pop band Take That, among others.

It was previously reported that several other A-list singers — including Sir Elton John — refused the king’s invite to perform at the three-day event.

Perry has faced online criticism multiple times this “Idol” season, first upsetting fans after seemingly “mom-shaming” young, quirky contestant Sara Beth Liebe during her audition and then begging her not to leave the long-running competition.

She also got booed by a Hawaiian audience for advising contestant Nutsa to dull down her sparkly costumes.

Last week, fans demanded that Perry apologize to contestant Wé Ani after the judge seemed to dismiss the hopeful’s haunting rendition of Adele’s “Skyfall” because she was shocked at America’s vote to eliminate other contestants.

“Idol” alums including Justin Guarini, Clay Akin, Jordin Sparks, David Archuleta, Phillip Phillips, Catie Turner, Noah Thompson and Adam Lambert have all appeared as Season 21 mentors.

Singer-songwriters Allen Stone and Noah Cyrus also stopped by to guide the contestants.