On the face of it Gary Cooper and Billy Crudup don’t have much in common. Cooper was the epitome of strong and silent reassurance and was said never to have played a dishonest man. Crudup is the shimmering enigma who has played a whole heap of them: a Kim Philbyesqe spy in The Good Shepherd, a slippery space captain in Alien: Covenant, a Machiavellian TV boss in The Morning Show, for which he won an Emmy last year. Even his Seventies rock star in Almost Famous (“I’m a golden god!”) had a certain unreliability.

Yet here Crudup is, taking on one of Cooper’s defining roles: Will Kane in High Noon, the upstanding marshal counting down the minutes until his face-off with a murderous outlaw. The beloved western of 1952 has been adapted for the West End stage by Eric Roth, the Hollywood heavyweight who wrote Dune and Killers of the Flower Moon and won a best adapted screenplay Oscar for Forrest Gump (1994). The play, which has its world premiere at the Harold Pinter Theatre, unfolds like the film in real time over an hour and a half and uses a ticking clock to crank up the tension.

“I’ve never played a part like this,” says the New York-born Crudup, 57, who has just finished a day of rehearsals in central London. “That kind of indefatigable moral certitude — not articulating it, just knowing it. It’s just a very hard thing to play.” Will he bring the same clarity that Cooper did? “I suspect what I will do is f*** that up.” He doesn’t mean mess it up, he means subvert it, because that’s what Crudup does. As he likes to point out, his surname is pronounced croo-dup, to rhyme with “screwed up”.

There are also physical differences between him and Cooper. “He was 6ft 3in so you understand physically how he’s a marshal. I’m 5ft 9in. You have to think about the different ways I might become a marshal.” Charm, guile and erudition for a start — plus menace when viewed in a certain light. People with moral certitude can be scary. “They’re just on the other side of being a lunatic,” Crudup says. “There’s a cultlike mentality to it.” Which sounds very much in his wheelhouse.

Billy Crudup and Naomi Watts at the premiere of "All's Fair."

Crudup with his wife, Naomi Watts

RICHARD SHOTWELL/INVISION/AP

If High Noon represents a leap for him, his role in Noah Baumbach’s latest film, Jay Kelly, feels deliciously appropriate. Baumbach has all kinds of fun casting George Clooney in the title role of a Hollywood star in crisis and there is a similar knowingness in his choice of Crudup to play Tim, Jay’s old acting buddy, who was always seen as the talented one. While Jay, like Clooney, became a star by playing variations on himself, Tim, like Crudup, committed to transforming himself into different characters.

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There is an extraordinary scene in which Tim demonstrates his Method acting genius by reading a menu in character, breaking down as he reaches the truffle parmigiano fries. Crudup doesn’t see himself as a Method actor but he can certainly convince as one — it may be the best example of someone playing an actor acting since his wife Naomi Watts’s audition scene in Mulholland Drive. “It’s a hilarious proximity to me,” he says. “I’ve got a lot of friends who I like to talk about this shit with.”

In Jay Kelly Tim has abandoned acting “like almost everybody who gets into it. It is disheartening, even in a successful career. I can guarantee Leonardo DiCaprio has roles that he wishes he got”, Crudup says. For him, the one that got away was the part in No Country for Old Men that went to Josh Brolin. “Cormac McCarthy was one of my favourite writers and the Coen brothers were some of my favourite film-makers, and I had just done a play with Frances McDormand [who is married to Joel Coen]. I thought, OK, I’ve got a good chance on this one. I wanted it so bad,” he says. “When I went and saw that motherf***er — that was never my part. That was Josh Brolin’s part to the bitter end.”

Billy Crudup as Timothy and George Clooney as Jay Kelly standing outside a restaurant called "Chez Jay."

Crudup and George Clooney in Jay Kelly

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Baumbach’s film shows how “we use a movie star as an analogue for the gilded life”, Crudup says, “when in fact that’s bullshit. There’s no correspondence between money and happiness.” Cate Blanchett, who starred with him in the wartime drama Charlotte Grey in 2001, once said that “Billy couldn’t give a rat’s patootie about celebrity” and it is clearly still the case, even if The Morning Show has raised his profile. That is not to suggest that his personal life hasn’t suffered, as Jay’s has in the film. “You end up missing some major features of your life — a wedding or a family member’s funeral or the birth of your nephew.”

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The three-month run of High Noon will mean more time away from Watts, whom he married in 2023 and lives with in New York. They know what they signed up for, though. Crudup is a stage veteran, having played the lead in the Broadway premiere of Tom Stoppard’s Arcadia and won a Tony for doing the same in Stoppard’s Coast of Utopia in 2007. He was last seen in London in Harry Clarke, a well-reviewed one-man show in which he played 19 characters. “That play was kind of overwhelming for me,” he says. “I would do it, then I would sleep as much as I could and then kind of stumble around in Camden and wait for the show to start again.”

Billy Crudup, Jason Lee, Mark Kozelek, and John Fedevich as fictional rock band Stillwater.

Crudup, front, in Almost Famous, a 2000 film about a fictional rock band

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Roth, who has adapted High Noon, is the opposite of a stage veteran — this is his first play. Luckily he had Thea Sharrock, the Brit who directed Daniel Radcliffe in Equus and Keira Knightley in The Misanthrope, to hold his hand. “Eric had never been in a rehearsal room,” Crudup says. “But Thea’s ability to articulate what we were doing, and his ability to pivot and learn a new skill, was miraculous.”

This High Noon is again set in the Old West, although there are parallels with the volatility of modern America. Lawlessness, Crudup says, “is probably the most natural state of America, when you go back to look at all the conflicts we’ve had”. The townsfolk, like many of their contemporary counterparts, are consumed by fear — in this case of the approaching baddie, Frank Miller.

Denise Gough and Billy Crudup sitting on chairs in a rehearsal room.

Crudup and Denise Gough during rehearsals for High Noon

In the film their refusal to help Will was seen as an allegory for the McCarthy witch hunts of the 1950s. The conservative actor John Wayne turned down the role of Will Kane on those grounds and the screenwriter Carl Foreman, a former member of the Communist Party, was blacklisted after refusing to name fellow members to the House Un-American Activities Committee. Today people are similarly afraid of putting their heads above the parapet, whether it’s over trans rights or Israel-Palestine. The play, Crudup says, “is not about courage, it’s about cowardice”.

A big difference this time is the role of Will’s wife, Amy, whom he has just married. On screen she was played by Grace Kelly and was quite modest. Here the part is beefed up and taken by Denise Gough, the Olivier-winning Irish star of People, Places and Things and the Star Wars series Andor. Crudup wasn’t familiar with Gough’s work but Watts had worked with her on a pilot for a Game of Thrones spin-off, Bloodmoon, later abandoned. Watts told him that Gough “is like a beast, she’s badass”, a verdict with which Crudup now strongly agrees.

Grace Kelly turns her back on Gary Cooper in a scene from the film 'High Noon'.

Gary Cooper and Grace Kelly in High Noon (1952)

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It must be nice to be able to say he is married to Watts. “I can’t disagree with you there,” Crudup says with a half smile. They got together after playing a married couple in the TV series Gypsy. Would they work together again? “We don’t have anything on the books right now but we talk about it often. She’s chomping at the bit to do some theatre.”

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Crudup hates talking about his personal life. When we last met in 2017 he quoted an episode of The Simpsons in which Homer becomes the PA to Alec Baldwin and Kim Basinger and sells their secrets to the tabloids. Defending his actions, the yellow one says: “If these big stars didn’t want people going through their garbage … they shouldn’t have tried to express themselves creatively.”

Yet, as Crudup’s journalist once told Natalie Portman’s Jackie Kennedy in Jackie, “You’ll have to share something personal eventually. People won’t stop asking until you do.” Especially when you have as turbulent a romantic history as Crudup. Before marrying Watts he was with Mary-Louise Parker, the star of The West Wing and Weeds, for seven years, but left her for Claire Danes (Homeland) when Parker was seven months pregnant with their son.

“You have to live with the mistakes that you make,” Crudup said in 2017 of that period. Are he and Parker on better terms now? “Well, without commenting on any of our … Our adoration for our son is boundless. And he has, through the mash-up of the two of us, been endowed with superpowers for theatricality.” William Atticus Parker, now 21, is an actor, director and writer who has already made several micro-budget films. “He’s such a badass,” Crudup says. “Mary-Louise and I appeared in most of his films.”

Jennifer Aniston and Reese Witherspoon holding hands while Billy Crudup smiles in the background.

Crudup with Jennifer Aniston and Reese Witherspoon in The Morning Show

APPLE TV

Once Crudup has finished High Noon he will start filming the fifth season of The Morning Show. Playing Cory Ellison, the impish head of a TV news network, is “so much fun”, he says, saluting the work ethic of his co-stars and executive producers Jennifer Aniston and Reese Witherspoon. “They’re just professional animals.” The storylines often pre-empt real life. In one episode Cory sees orange wildfire smoke and says, “Did they make Trump the pope?” The scene was shot before Trump’s re-election, the wildfires in Los Angeles and Pope Leo’s inauguration.

Like many actors Crudup had an itinerant childhood, moving from New York state to Texas and then Florida. His father was a bookie, conman, loan shark and salesman who “could not handle nine to five and always spoke as though everything was on the up and up. When he carried a gun, he had a positive spin on it”. Even when he was dying of cancer, his father put on an optimistic front. “He was not far off from death, shrivelled up, and I remember him muttering, ‘I’m going to beat it.’”

In the 2023 series Hello Tomorrow! Crudup played Jack Billings, a huckster salesman going door to door flogging timeshares on the moon to suburban suckers. “I was doing an impression of my dad,” he says. That, you suspect, is where Crudup got his charm and elusiveness. His father doesn’t sound like a great role model but he inadvertently taught his son some valuable lessons about performance.

At the Harold Pinter Theatre, London SW1, Dec 17 to Mar 7, atgtickets.com