It’s taken the actor 30 years to reach the A-list. But with his role as bad guy Orson Krennic, he’s about to go galactic. He talks about being awestruck by Darth Vader – and his lederhosen-wearing youth

Rogue One director Gareth Edwards has a nice story about Ben Mendelsohn – who is playing Orson Krennic, chief bad guy in the forthcoming offshoot of the Star Wars franchise. On the day that Darth Vader walked on to the set, says Edwards: “We were just getting ready to shoot the scene, and Ben asked to confer. It probably looked like we were huddling over actor stuff – motivation, tone, whatever. We weren’t. In fact, Ben was like a 10-year-old kid, clenching his fists in total delight and saying [he puts on an Aussie accent]: ‘Mate, look! It’s Darth fucking Vader!’”

Mendelsohn says: “It was like the seven-year-old me’s dream come true, 1977, Star Wars. From the ages of six to about 12, you’ll find that’s the peak age range where these movies go straight in – zoom!” He mimes a rocket flying into his face and blowing his kiddie-consciousness into a million pieces. “It hit me at an elemental level, and, for that kid I was then, I’m very glad. I often quip that there were many times in my life when I wish I’d been able to tell myself: ‘Don’t worry about it, one day you’ll be in a Star Wars movie.’ Alas, you can’t do it. And yet …” he chuckles, “here we are.”

Mendelsohn’s face is his fortune. As we talk at the Lucasfilm production offices in Presidio Park overlooking San Francisco Bay, I marvel at its languid expressiveness, one moment lordly, unexpectedly noble in profile, the next slovenly, lizardly rangy, a sneer rolling along his lips. Few actors have his degree of iron control over their faces; no one says more facially by doing less. His vocal dexterity is also remarkable. His talk is effervescent and brutally blunt by turns, punctuated by sharp barks of laughter and a goodly sprinkling of “fucks”, as he ranges widely – here in a tone appropriate to a biker bar at closing time, here in one more suited to bone-dry academia – on esoteric themes that appeal to him in the moment. Talking with him is a journey and a joy.

Facebook Twitter Pinterest Mendelsohn as Orson Krennic in Rogue One: A Star Wars Story. Photograph: Allstar/LucasFilm

A dapper fellow, he shows up in a surprisingly elegant knee-length brown greatcoat, easily the liveliest person in this tightly controlled junket environment. He has the demeanour of some savage, untamed indie actor, more accustomed to eating at petrol stations and crapping in buckets on some austerely frigid location-shoot, suddenly let loose amid the spoils, swag and heaving craft-service tables of a mega-budget A-list crowdpleaser: the very definition of a loose cannon.

Mendelsohn, now 47, has been a professional actor for nearly 30 years. But most people won’t have come across him until his blistering turn as the psychopathic elder brother in David Michôd’s Melbourne crime saga Animal Kingdom in 2010. Since then, he has given us a gallery of (mostly malevolent, usually funny, always complex) antiheroes and flat-out bad guys in movies as interesting and varied as Killing Them Softly, Starred Up, The Place Beyond the Pines, Black Sea and Slow West. On a parallel track, he has been slowly establishing himself in A-picture material, such as Ridley Scott’s Exodus: Gods and Kings, The Dark Knight Rises and Rogue One, and next year we’ll see him in his first Spielberg movie, Ready Player One, again as the main antagonist.

By the time he struck it big – or medium-big – in the US, Mendelsohn had almost given up on succeeding outside Australia. He had seen actors his own age, then younger, then much younger, bypass him on the way to Los Angeles and stardom. His career had started out with the hit nostalgia drama The Year My Voice Broke, in 1987, when he was 17; a film that came at the tail-end of the original Australian new wave of the late 70s (directed by one of the original new-wave heavy hitters, John Duigan). Mendelsohn played the charismatic, irresponsible, rugby-playing bad boy who stole cars and got girls pregnant, in a swaggeringly confident performance that earned him work in Australia for years after, but nowhere else.

Facebook Twitter Pinterest Mendelsohn as the psychopathic elder brother in the 2010 film Animal Kingdom. Photograph: Allstar/Maximum Films

In the decades that followed, he worked prolifically across the archipelago of diverse Australian film scenes that had sprung up separately in Melbourne, South Australia and Sydney, and kept busy. He is thus one of the youngest actors of the mature new wave, and one of the oldest of the seemingly never-ending new wave of Australians passing through the Neighbours set (like every Australian actor from Russell Crowe and Guy Pearce to Margot Robbie a generation later) and on to greater glory in Hollywood. He was on Neighbours before anyone else, and they all beat him to Los Angeles.

“I held the highest age-to-films ratio in Australia for a good few years. I really did do a lot of films, by Australian standards. Most of which didn’t travel. But I was also there for the start of Neighbours, with Kylie Minogue and Jason Donovan. I just predated it in my career by a couple of years. Kylie and I had done The Henderson Kids before that. I knew her from the time she was 15, and I heard her the first time she sang on stage, in a hall in Birregurra, doing a cover of The Rose by Bette Midler at the Hendersons wrap-party – it was actually a magical time.”

But the siren call of Hollywood never dimmed. “Now it’s much more possible for people to do one thing or two things in Australia and then go straight over – the path to LA has become a lot quicker, but was harder 20 years ago. It was pretty easy to start feeling one had been passed over and forgotten about, and I wasn’t gonna take that on the chin. And I did do it, kept going back but, for a long time, nothing came of it. I found myself having to think: ‘Well, that’s that.’”

He does pop up in odd places, if you are not aware of his past career. The night before I interviewed him, I caught him in a small but eye-catching role in the mountaineering thriller Vertical Limit, sobbing his eyes out in one scene, then being blown to bits 10 minutes later. And, if you watch carefully, you can spot him somewhere in Terrence Malick’s The New World. Patience, however, was his virtue.

Mendelsohn had a peripatetic upbringing, living in many places, mostly in Europe and in the US. He believes that rootlessness helped him as an actor, giving him a certain latitude to decide which Ben he would be in this “next life”, whenever he moved house, school or country, and how to write his own “character”.

“In this acting game,” he says, “there are a lot of army brats and people with moving-about childhoods. Moving around a lot and having to learn how to read what was coming up next, that thing of being able to read things and adjust accordingly, to find a way to make yourself fit in or feel a bit special, or different, is a lot like joining a new cast, really good practice.”

Most of this was outside Australia, which inevitably made him start feeling differently about the meaning of the word “home”, with Australia soon becoming another foreign place.

“I got back there for the first time when I was six, from living in Germany, and I had a thick German accent, and my mother had dressed us in these, almost semi-lederhosen, garish German, early-70s clothes. And it was a real shock. Australia was the real shock, it was where I learned to act, no doubt about it. And I returned to Australia twice at different crucial points in my schooling, and each time it was another kind of transformation.”

Facebook Twitter Pinterest Mendelsohn, aged 17, in the 1987 film that started his career, The Year My Voice Broke. Photograph: Avenue/Everett/Rex/Shutterstock

Mendelsohn arrived “home” just in time to witness the forcible removal from office in 1975 of modernising progressive prime minister Gough Whitlam by the governor general of Australia Sir John Kerr, the most scandalous usurpation of democracy in the nation’s history.

“When I got back there were lots of “WE WANT GOUGH!” badges everywhere. I remember that badge on the fridge at home, and understanding that it was our sworn duty to hate Malcolm Fraser! [Whitlam’s unelected replacement] If it wasn’t for Gough, you just wouldn’t have an Australia as you recognise it now. It gets its lifeblood from that government and what it achieved. And the reaction to Blue Poles [the Jackson Pollock painting purchased by the Whitlam government at enormous cost, solely to spur a national cultural conversation], and I do remember the reaction to it, even though I was very young, was … I mean, they were absolutely derisive about it! Australia was very elemental in the 70s, very raw, still kind of philistine. The Australian way, it is brutal, absolutely brutal at the merest whiff of, I mean, any airs and graces, you are for it. It’s a kind of ferocious egalitarianism. That’s very big in your culture and in ours, but not in the US at all. And it didn’t really start to shed that until the 1990s.” (Mendelsohn obviously loves his home country, but I note that he lives in Los Angeles with his wife of four years, British writer Emma Forrest.)

Funny thing: as good as he is, Mendelsohn doesn’t watch his own work. You should start, I tell him. Turns out you’re pretty good at this.

“I think I might start again. It began when I was doing some TV thing somewhere, and I didn’t want to watch it. Afterwards, I thought: ‘Oh, I got away with that!’ And I really think it helped make me better as an actor. There is a certain sense to that. There’s always some tinkering that you could have done, you feel. You watch things and think about how you could have got louder or thought differently, but worrying about that just gets to be a huge pain in the arse. No, maybe I won’t start watching myself again!”

When he was a kid, his acting heroes were John Wayne, Clint Eastwood, Al Pacino, Jeff Bridges (“the best, the most charismatic and beautiful, just a fantastic actor!”) and Jack Thompson. Since Animal Kingdom, Ben Mendelsohn has been proving over and over that he might well ascend into their company one day.

• Rogue One: A Star Wars Story is released on 15 December