He’s only 28 but we’ve already seen a lot of that ginger mop and long face, from the Harry Potter movies to True Grit. In his latest role he plays a farmer running a brothel. DONALD CLARKEmeets Domhnall Gleeson

IT SEEMS A LITTLE surprising that Domhnall Gleeson has only now secured his first lead in a feature film. Yes, he’s just 28. True, we’d barely heard of him five years ago. But that long face and untamed ginger mop – part Dickensian urchin, part beatnik tearaway – seem to have been everywhere in recent times. He moped beside Keira Knightley and Carey Mulligan in Never Let Me Go. He played a Weasley in the last two Harry Potter films. He was perfectly cast as a living daguerrotype in the Coen brothers’ reinvention of True Grit. One could forgive his inestimable dad – that’s Brendan, if you haven’t been paying attention – for looking nervously over his shoulder. The next generation is on the march.

“Those things can be deceptive,” he says. “A lot of stuff got released around the same time. I have been really lucky because I’ve already worked with heroes. It never quite feels that everything is going great. Because you’re always trying to do a good job and looking for the next good thing.”

Gleeson is an articulate fellow. Like his dad, he speaks in proper sentences that come together to form complete paragraphs. Still, the syntax does break down a little when I allude to the first scene in his current project. Tom Hall’s striking Sensation, a drama of debauchery from the Irish midlands, begins with our hero self-administering (ahem) manual relief in a desolate sheep-ridden field.

“Oh the masturbating,” he says, happy to get this out of the way early on. “My answer to that question is always the same: practice, practice, practice. Ha ha!”

Our facetiousness should not be allowed to distract from the serious nature of Hall’s quasi-comedy. The film finds a lonely farmer hiring a prostitute and then setting up his own brothel in a stark modern property. Interesting questions are being asked about our nation’s continuing queasiness when addressing sexuality.

“That’s 100 per cent correct,” he says. “They have dealt with that in the States: with social realism, with romantic comedy. But I can’t think of any Irish films that have sex as a central theme. So the idea of dealing with sex in an Irish context is really funny and really important. The notion of Irish men having sex still seems faintly ridiculous unless you’re Colin Farrell.”

Hall’s picture is very good on the way today’s younger people – even if they’ve yet to see a real bosom – learn a disturbing amount about the mechanics of sex from steamier corners of the internet. “That is terrifying,” Gleeson says. “It all used to be hearsay. You had just talked about it. If you actually found somebody to have sex with you were then on a voyage of discovery. Now you know everything. You’ve seen everything. You try to start on the ground floor. But it’s all distorted.”

Gleeson must be aware that every interview will, sooner or later, get around to the subject of his dad. Ponder the Gleeson archives and you realise that Domhnall must be old enough to remember his father’s steady rise from occasional actor to undisputed national treasure. That must have made for an interesting childhood.

“Yeah, I guess that’s right,” he says. “Mind you, if I described him as a national treasure he’d call me an asshole. But my memories before the age of 10 don’t really exist. I do remember dad being in theatre. That was exciting, but he was still just my dad. From a selfish point of view, I was able to see how difficult that job could be. I do remember when he was on Glenroe. That was a really big deal in school. But what was most important was that he was a great man. And my mam’s a great woman. Make sure you write that too.”

The elder Gleeson was indirectly responsible for Domhnall’s lunge into acting. After school, he studied at the Dublin Institute of Technology with a mind to becoming a film-maker. (His recent, amusing short, Noreen, starring Brendan and his brother Brian, shows a great deal of promise in that area.) Then he accepted an Irish Film and Television Academy Award for his father, who was busy elsewhere. His speech was so entertaining that the script for Martin McDonagh’s The Lieutenant of Inishmorewas put his way and, having never really intended to act, he suddenly found himself playing a key role in the Broadway production of that gruesome melodrama.

Earlier this year, Brendan returned the favour by picking up Domhnall’s Ifta, awarded for his performance as Bob Geldof in the TV drama When Harvey Met Bob.

“Yeah, I got a Bob Geldof thing,” he laughs. “That was a scary role. I got cast two weeks before we began shooting. I rented a flat in Rathmines and wandered around as Bob Geldof to get the walk right. I eventually met him on The Late Late Show. I met him backstage and he said: ‘Oh, I didn’t know you were playing me.’ Maybe he hated it. Maybe he didn’t see it. But he was very sweet. An incredible man.”

What really bumped Gleeson into the big leagues was, of course, the role of Bill Weasley in Harry Potter and the Deathly Hallows. It’s not a huge part, but membership of the Potter family bestows status on an actor. The experience also introduced him to the terrifying world of mega-budgeted movie-making. Veritable armies of well-paid professionals produce those films.

“We started off on a shoot in Wales with a ‘skeleton crew’ of about a hundred people,” he says. “That was easy. Then suddenly we were in the studio with 300 people. You have this tiny set, but the production is huge.

“I nearly vomited. But the great thing is that I will never be that nervous again. I may never have that many people looking at me again.” That experience allowed him to advance on to the set of True Gritwith a certain degree of confidence. Working with the Coens was, he explains, an extremely comfortable experience. Far from jabbering in dual cacophonies, Joel and Ethan would take turns to leave the camera and chat individually with the actors. “They were everything I hoped they would be,” he says.

With Hollywood now circling, it must be tempting to move to Los Angeles. But he feels that – not least because he can’t drive – he won’t be making the jump any time soon. Also, he is currently immersed in Joe Wright’s production of Anna Karenina. Keira Knightley plays the doomed heroine. Aaron Johnson is Vronsky. Gleeson plays the sensitive, troubled Levin. He can’t ever have imagined that, before reaching 30, he’d be asked to play a version of the young Leo Tolstoy.

“It’s safe to say I didn’t,” he says with a dry smile. “We’re shooting that in Shepperton and then in Russia. The fact I’ve been trusted with that is amazing. There are not many jobs like this in the world. I love travelling. And I love coming home.” He sounds like a sensible chap. National treasure status awaits.