James Corden left the premiere of “Cats” to start shooting his next musical movie, Page Six is told.

Corden recently revealed that he’s not yet seen “Cats,” admitting: “I’ve heard it’s terrible.” And we hear that he left the crowd at the NYC premiere of the film early to fly to LA to film the adaptation of another Broadway favorite, “The Prom.” The Brit comic plays Bustopher Jones in Tom Hooper’s adaptation of the Andrew Lloyd Webber musical. And although he trod the red carpet at the movie’s Lincoln Center debut on Dec. 16, Corden didn’t join the rest of the cast to introduce the movie, much to the “confusion” of Hooper.

An onlooker told us: “The director started introducing the cast, building up to Jennifer Hudson [and] Taylor Swift . . . When he called for Rebel [Wilson] and James, only Rebel walked out, and Tom repeated James’ name a couple more times.” The source recalled, “Finally, Rebel joked, ‘James has had enough, he’s not coming out!’ Tom just looked confused.”

Corden then didn’t attend a glitzy after-party at Tavern on the Green.

Insiders said that the premiere was running late and Corden had to jet back to LA for his 7 a.m. call time for “Prom.” A source insisted that studio reps were well aware of the situation, and that Corden waited till the last minute to leave.

Hooper admitted at the premiere: “I finished [the film] at 8 a.m. yesterday, after 36 hours in a row, putting the finishing touches on it.” After a critical drubbing, he and Universal took the unusual step of sending theaters a new version of the film with “improved” visual effects.

Speaking to BBC Radio 2 host Zoe Ball, Corden said: “I haven’t seen it, but I’ve heard it’s terrible . . . I’ll catch it one day, I imagine.” Ball responded: “The reviews have been a bit harsh.”

Meanwhile, Evan Rachel Wood posted a series of Instagram Stories giving an expletive-riddled review of the film, saying it “is actually worse than I thought it would be.”

Corden’s reps didn’t comment.