NEW YORK — When it came time for Noah Baumbach to cast “Jay Kelly,” his new comedy about a globally adored Hollywood movie star having a “What’s it all about?” midlife crisis, what did he do?

He got a real movie star: George Clooney.

The result has been applause for the writer-director (“Barbie,” “Marriage Story”) and a personal triumph for the star.

“The feeling early on,” Baumbach, 56, said at the film’s New York Film Festival premiere, “was for the big audience we wanted an actor who was a movie star.”

“Tom Cruise was busy,” Clooney, seated next to him, cracked.

“That’s what George said when I gave him the script. He said, ‘You’re lucky I’m saying yes, because there’s only about three people on Earth who could play this.’

“But I felt it was important this audience have a history and relationship with the actor playing Jay Kelly, the same way that people have with George.”

For film geeks Baumbach inserted references to classic autumnal movies by Ingmar Bergman and Federico Fellini while the score stirs in Charlie Chaplin’s heartbreaking “Smile.”

“I’ve been a giant fan of Noah’s work since the very first film I saw of his,” Clooney, 64, said. “When he sent me this script, I thought, ‘This is a beautiful story, beautifully written.’ He told me that Adam (Sandler) was going to be playing the manager right off the bat. Adam and I’ve known each other for a long time, 25 years.

“I worked with Laura (Dern) when she was 15 years old, which was like what? Eight years ago.” That was the now-infamous 1983 horror film “Grizzly II: Revenge.”

“The worst thing you could ever imagine. They ran out of money. We got stuck in Budapest! When it was ‘Communist Budapest’! The movie never came out — until two years ago. We get killed in the first scene — and it’s like, ‘Starring!’ (the two of them).”

While Clooney’s a natural as a movie star, Sandler and Dern play people actors know intimately but who are not well known: Jay Kelly’s manager Ron and his publicist Liz.

“We did give so much to this man that we were sacrificing some of ourselves, And that was painful,” Sandler said.

“Beyond the privilege of getting to play these roles and praise these people who’ve suffered through with such generosity,” Dern said, “their dedication to all our careers was amazing.

“I was so moved seeing the movie tonight, I just have to talk about the complexity and beauty of George’s performance.

“George, through this character, you carry us through our lifetime of wondering if we missed it.

“It just was so beautiful! How you transcend the character. Such an amazing gift.”

“Jay Kelly” is in theaters Nov. 21 and streams on Netflix Dec. 5

George Clooney as Jay Kelly and director Noah Baumbach on the set of “Jay Kelly.” (Peter Mountain/Netflix)