He was a DJ from Hackney struggling to find acting work when he landed the role of Stringer Bell, a hard-core Baltimore gangster in the cult TV show The Wire. Idris Elba has never looked back. Now, with his new film storming the US box office, he is even being talked about as the first black James Bond. He talks to Stuart Jeffries

Recently, one of Idris Elba's young relatives came up to him, rolled up his trouser leg and showed off some bite marks. Elba asked the teenager what had happened. "He said: 'Man from another corner set his pit bull on me.'" The kid, he goes on to explain, is dealing drugs on London's streets. "He needs help getting out of that world," says Elba.

Elba is telling this story in a Soho screening room before an audience of hard-core fans of the cult TV series The Wire, in which the Hackney-born actor excelled in the role of the venal, disgusting, but utterly captivating Baltimore drug kingpin Russell "Stringer" Bell. After the Q&A, the audience will get to see Elba's favourite instalment of the drama (episode 11 from season three - for those currently watching The Wire, a quick warning: there are spoilers ahead). Most of the people here know his character better than Elba does: they know that Bell was shot in that episode by charismatic hoodlum Omar Little and bow-tied assassin Brother Mouzone in a hit commissioned by his boss, Avon Barksdale. Elba, if he ever knew these nerdy details, has consigned them to oblivion. He claims not to have watched much of his work on the series and to be immune to his character's allure.

"I like this episode because Stringer dies in it," Elba says by way of introducing it. "I celebrate the fact that he dies. I have a problem with the glorification of a drug dealer and America is fascinated with that world. We're celebrating the very fucking problem that America has in its hood. But Stringer Bell was no role model. He ruled the people who worked for him through fear. So it was good that Stringer died." The lights go down on a rather stunned silence: the audience, if not the man who played him, loved String.

A couple of days later I meet Elba in a posh East End members' club and ask about his relative's story. There's one word that intrigues me, namely "corner". It's the word, after all, that the slingers, junkies and narcos in The Wire use to describe a drug gang's territory. I know diddly about the slang of illicit pharmaceutical retailing in London, but it just strikes me that maybe London is imitating the Baltimore of The Wire, as dealers sort out their turf wars.

"That word was around here before The Wire," he says. "For me, the point of the story is that what you see on The Wire is happening here. I find it hard to believe, especially that a kid from an African family sells drugs. Africans, we hold on to our youths and whip them into shape." Elba, whose father is Sierra Leonean and mother Ghanaian, pauses. "But you know what? I can't judge now. I'm 36 and I don't live here any more. Back in the day, the baddest thing I ever saw was a flick knife. If someone pulled out a gun, that wasn't the done thing. There was this English reaction: 'Put that away, put up your fists and let's sort this out.' Now things get sorted out with guns and knives.

"When I was a kid, I thought it was tough. I got beaten up. There was this bully who would nick your bike and ride it around and give it back to you messed up at the end of the day. Once he locked me and my bike in this 6ft by 4ft cupboard in the stairwell of the high rise we were living in. He lit a newspaper and threw it in. I was kicking to get out. That was terrifying, but I know it's harder for kids today."

Elba, who now lives mostly in Atlanta, Georgia, is visiting London, staying in his mum and dad's house in East Ham. "I'm back in the room I was in when I was 13 and started dreaming of making a mark as an actor like Marlon Brando or Robert De Niro." Today, Idris Elba is making a mark. Not just in The Wire, a series with which, after all, he finished with in 2004, but in his subsequent film and TV career. When he presented some awards at the Baftas last month, someone whispered that his latest movie had grossed a record-breaking $27.5m in its first weekend. "I looked around the room and there were all these stars - Jonathan Ross, Ross Kemp and Lenny Henry - and knew for the first time I was as good as them."

That film was Obsessed, a Fatal Attraction-like thriller in which he takes the Michael Douglas role, Beyoncé Knowles plays his wife and Ali Larter plays the misogynists' dream, a crazed blonde who wants to get into Elba's pants and ruin his perfect marriage. It takes all three leads' acting skills to transform the script, which seems to have spooled from the programmable keys on some hack's laptop, into box-office paydirt.

The biggest difference between Obsessed and Fatal Attraction is that Idris Elba's character doesn't have consensual sex with his ill-motivated, crackpot stalker. As a result, Elba's character is less interestingly blameworthy than its prototype. Ultimately, he has to step aside so his wife can take out the trash. Elba makes as much as is possible with such a symbolically castrated role.

What is Elba's take on the film's success? "America has been obsessing about politics for the past year. The country was just like 'Give me a break.' This is entertainment, something to take America away from that world."

More seriously, he fumes over the New York Times's review. "The critic hated it. Fine. But the last paragraph was ridiculous." That paragraph reads: "The movie's most disturbing aspect, of which the film-makers could not have been unaware, is the physical resemblance between Elba and Larter to OJ and Nicole Brown Simpson. It lends Obsessed a distasteful taint of exploitation."

Hold on, I say to Elba, this guy reckons you look like OJ? Elba purses his lips crossly and nods his head. Let me assure you that you don't. If Elba does resemble a footballer, it's one from this side of the pond: he has the smiling eyes and good looks of ex-Spurs striker Les Ferdinand.

Is the idea that because you're big and black [Elba is nearly 6ft 3ins and has the build of an American footballer] and the femme fatale is blonde and white, you're OJ? "I think so. The acceptance of integration is immature in America. In England, it's not so much of a thing. In America, having a black guy and a white girl is a difficult thing for them to get their heads around. That's why Jungle Fever [Spike Lee's 1991 film about a black architect (Wesley Snipes) having an affair with a white woman (Annabella Sciorra)] was such a big deal there."

Surely you're not dissing America? "Absolutely not. Unlike here, in the US there are lead roles for black actors. That's why I went to America - to get the lead roles that I wouldn't here." Does starring in Obsessed, then, give you a sense that you've arrived? "It's where I wanted to be. I wanted to be the lead, not just the black lead."

No matter what the critics think, Obsessed is bossing the US box office and Elba's thespian stock has risen through the roof as a result. So much so now that critics are already talking about him as the first black James Bond. "There was this thing on CNN where they had a discussion saying that if there's a black president in the white House we now need a black Bond. And then the idea just spread like a virus. People kept coming up with ideas as to who should play the role, and then people in the blogosphere said what about Idris Elba. Even Daniel Craig [the current 007] said in an interview that the world is ready for a black Bond."

Indeed, Craig said recently: "After Barack Obama's victory I think we might have reached the moment for a [sic] coloured 007. I think the role could easily be played by a black actor, because the character created by Ian Fleming in the 50s has undergone a great deal of evolution and continues to be updated."

So would you fancy a spin as the legendary superspy? "Who wouldn't like to play Bond?

Do I think it will happen? No, but I've got what it takes to do it. I can run around, flirt with ladies and drink. Plus I'm English." But he has a rival. Rap star turned movie mogul Sean "Diddy" Combs has his sights on 007 and has even fashioned new TV ads for his fragrance line to give Bond bosses a good idea of what he'd look like as the spy. But unfortunately for P Diddy, he isn't English. The fact that Elba, the Hackney boy made good, is being considered for the role shows how far he has come.

So anyway, I say to Elba, you escaped, reinventing yourself along the way as an actor with a good American accent. Unlike so many others from your background, including your relative. "Well, yeah. That's not to say he won't get away, because he might. But he needs the kind of help that I got." Elba had a few kinds of help that made all the difference. "My parents always cared about my welfare." But his parents couldn't do everything for him. "They were poor. When I passed the audition to get into the National Youth Music Theatre, my mother said: 'You can't go. We haven't got the money.'" So Elba went to see his school drama teacher, who advised him to apply to a grant from the Prince's Trust, the charity set up by Prince Charles to help young people. "Without that £1,500, I don't know what I'd have become. It got me into drama school."

When I first meet Elba, he is chatting to some young men and women, mostly aspiring actors, wannabe sports stars or musicians, who have also benefited from the Prince's Trust. They've been invited along to hear his Q&A about The Wire, but before they do, they get to meet someone who has arrived where they want to go. In the room, there are people who are crawling from the wreckage of their earlier lives, from broken families, unemployment and the lack of confidence that comes with being from the wrong race or class in modern Britain. For example, there is one 25-year-old man with a CV that reads like one of The Wire's low-level slingers. His father was absent for most of his childhood, so he looked up to local gangsters and this led him into a world of organised crime, armed robbery, kidnap and drugs-selling, finally spending a year in jail for his crimes.

Suave and basking in a successful career, Elba is inspirational to his audience. He tells them about the book that helped him (Paolo Coelho's The Alchemist: "It reminds you we have choices and that it's important to make them. I've read it twice a year since I was 26"), about the film he admires ("I recommend you see what Meryl Streep does in Doubt"), and then takes questions. One young actor asks what she should do when she feels like jacking it in. "Don't be discouraged," says Elba. "It's easy to complain, but take that energy and use it and take that £17.50 you earned that week and spend it on seeing a play that will inspire you." Another aspiring actor asks him about his biggest regret. "There are a lot of regrets from my personal life," says Elba, who is divorced from the wife of his only child. "But in my career, my main regret has been not being 100% committed to something and getting praise for it when I know what I've done has been half-arsed."

Did you connect with those kids, I ask Elba two days later. "Yeah, but their stories are very different from mine. My parents kept me on the straight and narrow. Some of those kids weren't so lucky." Did your parents want you to become an actor? "No, they couldn't

see any money in it." What then? "They saw me in something manual. I wasn't bad at school, but I was never a bookworm. My dad wanted me to be a footballer, even though he didn't think English kids like me were as good as African footballers." Were you a good footballer? "Yeah. I could have done that. If it hadn't have been acting, though, I guess it would have been music."

Elba still works as a DJ, using the name Big Driis or, when in the US (where he's been known to hang with Ludacris and P Diddy), Big Driis the Londoner. He has released a hip-hop record and worked with Jay-Z on his 2007 album American Gangster.

"I think the thing for talented people is that they can turn themselves in any direction. I'm one of those people who've been able to do anything." He doesn't say this boastfully, just in the pleasant realisation of the proposition's truth. Elba has an enviable confidence about him, even to the extent of talking of himself in the third person. "If Idris had been a footballer now, he'd have been coming to the end of his career now," he says. "I could have been like Vinnie Jones." Indeed, like Jones, Elba has done time as one of Guy Ritchie's mockney herberts, playing Mumbles in Mr Madonna's widely derided Rocknrolla.

Elba is now fiddling with his stocking cap. It's one of those caps that The Wire's Preston "Bodie" Broadus wore when slinging drugs outside Baltimore low rises. I half expect Elba to fire a jet of spit, Bodie-style, from the side of his mouth; instead, he sets about a mushroom omelette and offers to share his toast.

After his late breakfast, Elba tells me how he made his name as an actor. His first assignments were hardly glamorous. He worked the night shift at Ford in Dagenham and then, by day, played in burglary reconstructions for Crimewatch, nicely demonstrating the institutionalised racism of the British media and society. "That was about the first on-screen acting I did. All the time I was trying to get agents to come and see me when I did pub theatre. Only one did and thanks to her I got roles that weren't those roles just for black men. Even so, I could see my career being like those of black British actors I admire, such as Colin Salmon or Adrian Lester. I wanted something different. In the end, I realised that if I wanted to be all I could be, I would have to go to the US."

So he moved to New York. One problem: the accent. "It took me three years to get it right and during that time I wasn't working there at all. I kept flying back for acting jobs over here, but it wasn't exactly cost effective." Eventually, he nailed that accent and the roles started coming. He joined The Wire after impressing in Law & Order, along with a string of actors from this side of the Atlantic (such as Dominic West, who played Detective McNulty, and Aiden Gillen, who played Mayor Carcetti).

"I auditioned for Avon Barksdale [Stringer Bell's drugs boss] and when I didn't get it, it was a kick in the teeth. But on the same day my baby girl [Isan, who is now aged seven] was born, they told me I'd got the part as Stringer." The role only had a few lines in the first season, but his character became infinitely more interesting than Barksdale. Bell had aspirations to leave the dealing behind and become a legitimate property developer. "He had the intelligence to take classes in economics, I'll give him that," Elba says of Stringer. When Detective McNulty, finds a copy of capitalism's foundational text, Adam Smith's The Wealth of Nations, in Bell's apartment, he says, mystified: "What the fuck was I chasing?"

Bell was hardly your average drug-dealing thug. [Spoiler alert] It's symptomatic of The Wire's dismal prognostications for African-American men from Baltimore's mean streets that Bell had the most considered exit strategy of any of them, and died within a whisker of making his escape.

After that, Elba decided he would make a career move. "It would have been easy to have played Stringer roles for ever. Like I told those kids, you've got to move out of your comfort zone, try something new all the time. I never want to play anything like Stringer Bell ever again." He is now in the US version of The Office, which he describes as "the most dynamic and sophisticated comedy to hit television in the last 10 years."

As it happens, his next film role is likely to be a drug dealer. In The Finest he is to play one of London's most feared Yardie gangsters. But there is a twist. He's also a bent undercover copper. "I don't want to say too much about it, but I think I could make the role really iconic, really special." Elba says he plans to keep that switchback ride of roles on both sides of the Atlantic going for a good while yet. His new-found Hollywood success, though, may change that career strategy.

Are you enjoying your success? "I'd throw it all away tomorrow for my baby girl," says Elba, who lives near his daughter and his ex-wife Kim Elba. He gets his reality checks, not just from his daughter, but from his parents. "They're so removed from what I do and at the same time they're very protective of me, because I'm their only child. I tell them that Obsessed is breaking box-office records and that I'm going to be interviewed on the Paul O'Grady Show, and my mum says, 'Oh, that's good. Did you eat today?' I need that stuff more than ever" ·

• Obsessed opens on 29 May

• This article was amended on 21 November 2011 to correct the name of Idris Elba's former wife.