Chris O'Dowd: From 'hunchback' to Hollywood heart-throb

The newly desirable actor talks to Genevieve Roberts about how he fell down a rabbit hole into a Wonderland of A-list movies

Chris O'Dowd is sitting in the dining room of Dean Street Townhouse, and at six-foot-four he's too tall for the exceedingly low chairs. "What is this? I mean, give me a chance," he says, entirely affably. "It's like I've come here and they're ridiculing me, it's like I'm Alice in Wonderland."

The Alice sensation of falling down a rabbit hole may be a familiar one. A Grand Prix year has seen O'Dowd, until last summer best known for his role in cult comedy The IT Crowd, become a household name for playing Officer Rhodes in Bridesmaids – and an unexpected heart-throb. He's had marriage proposals over Twitter, and he's been described as one of Hollywood's leading actors – "ridiculous", he says.

He's taking his new eligibility in his stride. "What's not to love? Of course it's silly – I'm very conscious of that. Whatever women found attractive about the character is about having a guy who really cares, is emotionally available and wants to put himself on the line for you," he says, in his trademark Irish brogue. "Jon Hamm's character is so repulsive that people are almost shoehorned into finding my character attractive. It's a very brief flirtation with heart-throbness."

The film was such a success that he's already shot two more movies with the same crowd. Friends with Kids, out in spring, is about thirty-somethings who start having children. Kristen Wiig plays a character married to Jon Hamm, while O'Dowd's married to Maya Rudolph.

The premise echoes his own early-thirties life – albeit in Bermondsey, south London, not New York – living with his girlfriend, writer and presenter Dawn Porter. "Everybody I know is doing it," he says. "I'm still negotiating. You get to the stage when you're with a woman who really loves her career, as she should, that it turns into negotiation, timeframes and under-the-table deals."

Not that he's keen to have children quite yet. "But I know at some stage I will. I'd like three kids, let's say, and I don't want to be old, so you have to start sometime – though right now I can't think of anything worse. It was easier for our parents, particularly in Ireland, because there was no contraception, so you just did it. Now it's difficult."

He also plays a record-company hipster in This is Forty, a spin-off of Knocked Up. He believes its release – showcasing him with bad moustache, slightly too tight T-shirt and silver jewellery – will be the end of his eligibility. "Done. I'm so aware of the fleeting nature of attraction." He modelled himself on the worst side of "hipster Hoxton", an area he says he is resentful of. "I've never been cool, so watching people for whom that's their life, is intimidating."

He's chatting to me because he's hosting the Moët British Independent Film Awards today, with Tinker Tailor Soldier Spy and We Need to Talk About Kevin competing for Best Independent Film. "It gives that spine-chilling fear of a blank page. I'm enjoying it, but don't think I'd do it for anything other than this type of award, where there's low expectation."

Alongside lots of acting and hosting offers, he's taken on major writing projects. Last month, he sold a pilot to NBC for a show about a male weight-loss group. "It's not about making fun of fat people," he says. "It's more about the way modern men talk with their buddies." He says that 10 years ago a chat between him and his best mate would have been about football or girls. "Now, there's a good chance it would be about where to get a vertically striped shirt."

And he's just got funding to write a film with his brother, 10 years his senior, about his travels to Australia in the early Nineties when he believed he had got a girl pregnant only to discover that she'd lied in an argument.

He's also working on Moone Boy, a semi-autobiographical series about life in Boyle in Ireland as a 12-year-old boy with an imaginary friend, who is scared of Father Christmas. He shows me a picture of himself with his four brothers and sisters, alongside Santa Claus. There's a wet patch on his shorts. "I think it was the whole idea of a man coming into our house," he says. "And we're feeding him? I was the youngest of five, and we didn't have a lot of money, so there were lots of hand-me-down presents – so there wasn't even a good payoff."

He describes his 12-year-old self as "vile". "Six foot, I had a massive nose and ears. Acne. I looked like I had a perm. No one would dance with the hunchback in the corner."

His teenage years continued in the same vein. "I was sporty so I got by. But when all you want is to touch girls, and that's the last thing they want, that's difficult for a hunchback." So he started being funny.

He moved to London at 20, after not-quite-completing his degree in politics and sociology at University College Dublin; working on building sites, in bars and at call centres, while pushing acting. They weren't wild years. "I'm a relationship guy. I went out with a girl, from 20 to 28, who I met at university. I've been single for eight months in 11 years. I learnt from experience how difficult it was to seduce women, so I cling on," he laughs.

This year may feel like a Wonderland experience, but O'Dowd has remained entirely grounded. He may be near-constantly on screen next year, but will continue working in indy films, rather than massive budget movies such as the Gulliver's Travels flop, where, "entire scenes were re-shot because someone crazy doesn't like hats". And while he may be slightly baffled at his level of success, he's not taking it for granted. "It never occurred to me that things would take this direction. I've not had too many bad times, but enough to let me know when the good have arrived."