On any given day, Mr Sam Rockwell’s appearance might suggest just-woken weariness: all perpetually tousled hair and sleepy eyes. However, on this December afternoon, as the 51-year-old actor ambles into the lobby of the Chateau Marmont hotel in West Hollywood, there is no hiding the fact his biorhythms are stuck in a low cycle, as they say in Los Angeles. Mr Rockwell yawns, long and deep. “F*** me,” he says, yawning again. He shudder-shakes his head and stretches his arms. “Sorry, this is crazy. I have got to wake up, baby.”

By Mr Rockwell’s side, as she has been for a dozen years now, is his partner, the actress Ms Leslie Bibb. After an exchange of farewells, the two share a long kiss and keep their hands entwined as they part, letting go only after several steps away from each other. Although the couple first met at the Chateau while Mr Rockwell was filming Frost/Nixon, this isn’t an anniversary or romantic getaway, just a work-enabled rendezvous at a storied venue that holds a place in their personal stories. Back in 2007, following their meet-cute, Mr Rockwell wooed Ms Bibb over the course of a long day-date surveying the sculpture and art at the Getty Museum. He won’t have a moment of leisure time on this visit – after shooting for nearly a year straight, he’s deep in promotion circuit, which he finds even more exhausting. But then, neither will Ms Bibb. “She has been working her ass off,” Mr Rockwell says. “She’s shooting here now, and she’s been in Toronto on her Netflix show. She plays a superhero. I mean, isn’t that fitting?”

This is something Mr Rockwell does, and not just about his real-life love interest. Practiced in the art of deflection and self-deprecation, he preemptively praises friends, collaborators and actors he admires rather than discuss his own achievements. In 2019 alone, those achievements include the biographical miniseries Fosse/Verdon, Mr Clint Eastwood’s drama Richard Jewell, and Mr Taika Waititi’s audacious anti-hate satire Jojo Rabbit. For example, ask Mr Rockwell about his work in the latter and he’ll shift the discussion to his co-star Ms Scarlett Johansson and the numerous nominations she’s racked up. “She’s kicking some ass,” he says. “I knew her from Iron Man 2. She’s beat me up in two movies now!”

As we make our way to the bar, we encounter Ms Bibb, who is thanking the bartender on her way out. “I checked,” she tells Mr Rockwell. “They do have the good stuff. OK, I love you, Boo-boo.”

“I love you too, baby.”

Watching this scene unfold – a couple excited to toast each other with a bottle from atop the wine list – it’s possible to imagine the rom-com version of Mr Rockwell. Someone who chose the road more travelled rather than the winding path of independent film, avant-garde theatre and Broadway plays, and offbeat, off-colour performances. But even in his domestic bliss, Mr Rockwell eschews convention: marriage and kids are fine for others, but not his cup of tea.

As he slides into the bar’s corner banquette, Mr Rockwell reveals a bottle he’s been carrying in the crook of his arm. “I’d offer to pour you some of this,” he says. “But my mouth has been on it.” He assumes no one would want to risk swapping spit with a man who’s played so many degenerates, boozehounds and ne’er-do-wells. But considering his recent run of success – an Academy Award, a Bafta and a Golden Globe for Three Billboards Outside Ebbing, Missouri in 2018 as well as nominations for each of those in 2019 for Vice, with the possibility of more to come this awards season – it seems clear there’s a thirst for whatever he’s serving. Mr Rockwell again sips from the bottle‚ which turns out to be Evian sparkling water, for which he seems apologetic. “If I wasn’t doing Corden later, we could get hammered,” he adds, flashing a roguish grin. “A couple of negronis. Or whiskeys. Or both, f*** it.”

Technically, Mr Rockwell is indeed appearing on The Late Late Show With James Corden to promote Richard Jewell. However, Mr Corden himself won’t be on hand this evening; the role of talk show host will be played by an understudy, one Mr Jeff Goldblum. Turns out, Mr Rockwell is familiar and, largely, comfortable with the concept of being second string. He wasn’t initially tapped for the role of attorney Mr Watson Bryant in Richard Jewell – Mr Leonardo DiCaprio was.

“That’s the way it always is. I wasn’t the first choice for a lot of things,” Mr Rockwell says, rattling off a list of roles he got only after others pulled out. But Richard Jewell also shows how far Mr Rockwell’s star has risen. When the project stalled, bounced around directors and landed with Mr Eastwood, Mr Rockwell was the legendary director’s first casting choice. “It was the weirdest thing,” he says. “I just got offered the part. There was no conversation. The agent calls: ‘Clint wants you for this thing.’” He shrugs. “I guess because of the Oscar and stuff. I guess?”

Mr Rockwell utters all this with the bemused inflection of an incredulous question, raising his eyebrows and squinting his eyes. It’s a look he has flashed onscreen many times; that blend of surprise and bewilderment is one of his signature affects, but seems sincere. It’s as if, after nearly three decades of hard work, he can’t entirely accept the scale of his success. Mr Rockwell has become the rare supporting player to whom top directors turn to carry their films, and a character actor to rival his 1970s idols Messrs Robert Duvall, Jon Voight and Gene Hackman, and his late friend Mr Philip Seymour Hoffman. “We all looked up to Phil,” he says. “Phil was the guy for my generation. He was a good lesson. Phil was not vain as an actor. And that’s probably my one fault: I am vain.”

For proof, Mr Rockwell waves his hand down his chest. “I mean, look at this shirt,” he says. Indeed, his red, white and blue tie-dye Prabal Gurung pullover and matching socks are eye-popping, even paired with a sedate slim-cut black suit and Italian Oxfords. “It’s something Klenzendorf would draw,” he adds, referring to his character in Jojo Rabbit, the closeted glass-eyed Wehrmacht washout who leads the titular 10-year-old Jojo’s Hitler Youth troop and sketches flamboyant fashion designs in his spare time.

In _Richard Jewell_­, which tells the story of the hero security guard who discovered explosives in the 1996 Olympic bombing in Atlanta’s Centennial Park and is then falsely accused of planting them, Mr Rockwell plays the part of Mr Watson Bryant, a salty, skeptical and intelligent lawyer. This part, too, plays to Mr Rockwell’s self-purported vanity. “It felt good to play someone smart. It’s been a while,” he says with a laugh. He was drawn to Mr Bryant’s anti-authoritarian ethos. “He’s a real anarchist. He’s a wild dude, a bronco that you have to wrestle down,” Mr Rockwell says. “He’s like a character out of a Tennessee Williams play.”

This is not the fanciful interpretation of a dramaturge; Mr Rockwell spent long hours with the real Mr Bryant, learning his mannerisms and intonation. He would relax by doing cinematic research – watching films such as Of Mice And Men, The Last Detail and Rain Man – with Mr Paul Walter Hauser, a relative newcomer in Hollywood who plays the titular Mr Jewell and whom Mr Rockwell took under his wing during filming. “I definitely like the flashy parts,” he says of playing the part of a mentor (both on- and off-screen), the supporting character. “I’ve done plenty of scene-stealing and that kind of stuff, and I’m OK being the other guy now and then.”

Mr Rockwell grew up in San Francisco, the child of parents who dabbled as actors and supported him when he pursued the craft as a child. “I got the bug, then I fell out of it,” he says, “I did some juvenile delinquent stuff.” He mentions shoplifting and an arrest for buying alcohol while underage. Mr Rockwell studied drama at a high school for the arts, but received poor grades. “I didn’t really take it seriously,” he says. “Then, randomly, I auditioned for a movie.”

Mr Rockwell landed a lead part in the film, Clownhouse, a slasher flick that became a horror story in real life when the filmmaker was arrested (and later convicted) for sexually assaulting one of the underage actors during production. In a strange turn of events, none other than Mr Francis Ford Coppola (who had financed the film) stepped in. Working with Mr Coppola was transformative. “That gave me some confidence to go to New York and pursue acting, and I really just went there looking for some adventure and to see what happens.”

He became a fixture of New York’s downtown scene and a member of the cadre of stage-first actors that included Messrs Jeffrey Wright, Liev Schreiber, Billy Crudup, Michael Shannon, Peter Dinklage and Philip Seymour Hoffman. He spent the bulk of the 1990s making independent films and waxes nostalgic for the form – “It’s sort of dying out. It’s a different thing now, isn’t it?” – though not for his early work. (“I was terrible,” he says, remembering one poor performance.) Since then, he’s appeared in everything from blockbusters including Charlie’s Angels and Iron Man 2 to cult favorites such as Moon.

“There’s something lovable about him even when he’s playing dark and dangerous characters,” according to Mr Martin McDonagh, who directed Mr Rockwell in parts he’d written for him in Seven Psychopaths and Three Billboards. “You have to have someone who has the integrity to be truthful to the darkness, but whose humanity will also shine through.”

This is no mean feat, which helps explain Mr Rockwell’s residual fatigue. He’s constitutionally unable to give anything less than full obsessive immersion. There is no throwaway role, no part he simply skims through. His Richard Jewell co-star, Ms Olivia Wilde, describes Mr Rockwell’s script pages as crumbled and dog-eared, covered with hand-scrawled notes and wine stains. (“Hey now, that was coffee,” he says, not really disputing the description.) Mr Rockwell’s mono-maniacal focus has made the past few years rewarding and gruelling in equal measure.

Leaning close, the actor seems to be about to reveal a secret. “Things are good. I’m happy with everything I’ve done, and I want to keep it going. But I need a break,” he says, nodding his head as if justifying it to himself.

As we pay the bill, Mr Rockwell reveals he has one project in the pipeline. “I’m not exactly going to get a break, because it’s pretty much non-stop,” he says. He will begin rehearsals for a Broadway revival of Mr David Mamet’s American Buffalo, in which he’ll star alongside Messrs Laurence Fishburne and Darren Criss. Returning to the theatre is imperative for him, both as a touchstone and a check against losing his chops. “It’s time to get back on there. Get back on the boards,” he says of the stage. “Got to go see what you’re made of and get your muscles back.”

For the first time in years, Mr Rockwell doesn’t have a movie in the works. “I’ve got a couple of scripts coming in,” he says. “A couple of friends I might work with again, but I don’t know. I’ve got to do one thing at a time, so the play is kind of it. This is it, bro.”

He shrugs and smiles, as that last statement is a bit of double entendre. It’s also time for us to part. We’ve emerged from the Chateau, overlooking Sunset Boulevard, which is thick with rush-hour traffic. “Look, it’s not a bad thing,” Mr Rockwell continues. “Treat every acting job like it might be your last and the last thing people see you in.” He leans over to give me a bear-hug goodbye. “So, I’m going to do a play, and I guess I’ll disappear from the planet Earth for a while. I’ll be back.”

With that, Mr Rockwell steps off the curb and waves as he begins making his way upstream against the current of stop-and-go traffic in search of his ride.

Richard Jewell is out now (US); out 31 January (UK). Jojo Rabbit is out now