Heard the one about Channel 4?

He's a funny guy, Noel Fielding, the smaller half of The Mighty Boosh, the one with the glam rock haircut. But you probably wouldn't ask him to define comedy, which is a key ambition for Channel 4 as it enters an era of creative renewal beyond Big Brother.

Nonetheless, the broadcaster has put the question to the eccentric Fielding, and "boopus" is the word he has come up with. Boopus, a term that refers to a part female cartoon character and part Roman legionary, will be the title of Fielding's debut solo comedy project and no one appears to know what it means, certainly not Shane Allen, Channel 4's head of comedy. "He wanted a fantastical name," Allen says. "He's a brilliant, inventive, comedic whirlwind of madness. It's like a kids' programme meets Spike Milligan. Him doing loads of rich characters that are part live action, part animation, and are all from Noel's amazing head. He's at the height of his powers and you have just got to let him get on with it and come up with something that's unlike anything on telly."

It's probably just as well that Boopus, which will be shown on E4, is just part of a multi-pronged Channel 4 strategy to take control of television comedy. At the salient of that advance is the British Comedy Awards, recently captured from ITV and now to be repackaged as eight hours of programming fronted by Bill Bailey and Jonathan Ross. The broadcaster has also given a show to Chris Addison, the star of the BBC satire The Thick of It. It has found fresh vehicles for three stars of the breakout E4 hit The Inbetweeners and is about to launch a comedian whom it sees as a female version of Kenny Everett. Channel 4 may yet come to define television comedy for this decade the way that Harry Enfield, Ben Elton and Saturday Live helped it to own the genre in the Eighties.

The broadcaster's plans can only be helped by the current lack of confidence at the BBC, which is being horsewhipped by the Government over its finances and has recently reissued its editorial guidelines to prevent recurrences of Sachsgate, limiting opportunities for risqué comedy. Such a climate has helped Channel 4 to lure away the Scottish funny man Frankie Boyle, who earlier this year described the BBC as being "cravenly afraid of giving offence" after it rebuked him for jokes about Palestine and the swimmer Rebecca Adlington.

Allen, by contrast, is excited that Frankie Boyle's Tramadol Nights (named after an analgesic) will start on Channel 4 in November. "With someone like Frankie, who comes from a tradition of Glaswegian working-class humour that goes back to Billy Connolly, there are scabrous ways of expression that you don't want to water down," he says, "especially at a moment when you want people to have a pop at authority and take the piss out of hypocritical and overpaid celebrities. Frankie taps into all that."

So Boyle, who "felt straitjacketed" on the BBC's Mock the Week, will be allowed to mix his stand-up with sketch material. "It's more cartoony and silly," Allen says. "There are ideas like George Michael's Highway Code, which is an animation... mirror, signal, wank, crash. Frankie does all the taboo stuff and with such intelligence."

But Allen, speaking on the first anniversary of his appointment, doesn't want Channel 4 comedy to be seen as just dangerous and strange. "Because Channel 4 is known for doing subversive things, that gets translated into a reputation for weird, niche, dark comedy, and we are fighting against that," he says. "Look at The IT Crowd and Peter Kay's work and the fact that we are doing the British Comedy Awards; it's warm and inclusive. We want to have stars and hit shows. Being niche and weird is not necessarily groundbreaking."

Chris Addison is part of that inclusive approach. While Mock the Week felt like a straitjacket to Boyle, Channel 4's new star Addison sees that show as being unnecessarily spiteful. "We talked to him about what he'd like to do and he wants to do a show that is unlike those panel shows where it's all about who can do the harshest joke," Allen says. So Chris Addison's Show & Tell will see the actor known for playing a headmaster in the teen drama Skins and political adviser Ollie in The Thick of It hosting a show alongside three up-and-coming comedians.

Allen likes to give comedians their head, to shape their own formats. He has an infectious humour and formerly worked on seminal programmes The 11 O'Clock Show with Sacha Baron Cohen and Ricky Gervais and Brass Eye with Chris Morris. Growing up in Belfast in the Eighties, he used comedy as an escape mechanism when attending a Catholic primary school and a Protestant grammar school. "I loved comedy the most between the ages of 14 and 17 when I learnt it off by heart," he says. "I always remember that because a lot of telly is made by middle-aged, middle-class people for other middle-aged, middle-class people, but it's the teenagers that take it to heart most."

The childhood "comedy snob" admits to frustration that the cognoscenti have not yet latched on to E4's PhoneShop, a heavily researched show that mines material from the cut-throat, streetwise culture of telecommunications sales outlets. "Why isn't everyone loving this already?" he says of a programme which he hopes will emulate its E4 stablemate The Inbetweeners, which gets its own feature film next year.

Simon Bird and Joe Thomas from The Inbetweeners will star in Chickens, a Channel 4 comedy set during the First World War. Bird will also appear in Friday Night Dinner, a Channel 4 sitcom based on the Jewish tradition of a weekly family meal. Another member of The Inbetweeners, Blake Harrison, appears in The Increasingly Poor Decisions of Todd Margaret, which is co-funded by the American channel IFC and will be More4's first venture into sitcoms.

And he's taking another risk on Morgana Robinson, 27, who managed to get noticed by taking a waitress job in a Japanese restaurant in Charlotte Street, the heartland of London's media land. When the agent John Noel came in for a meal, she gave him her showreel. Her show, The Morgana Show, features sketches and impressions of Cheryl Cole, Fearne Cotton and Boris Johnson (as a 12-year-old). Robinson is a "cross between Caroline Aherne and Kenny Everett", Allen says. "Some people might think it's a bit too broad, but it's the same with Peter Kay and you can't be a snob about it, you've just got to go for people with funny bones."

The Morgana Show will be shown on Friday nights on Channel 4 from the end of next month, alongside Peep Show, which has become Channel 4's longest-running comedy as it enters its seventh series. In the first episode, we will see Sophie having Mark's baby while David Mitchell's character almost has a breakdown coming to terms with becoming a father. We later get to meet Mark's parents for the first time. The show's longevity will be celebrated with a Peep Show night on Christmas Eve and Mitchell's co-star, Robert Webb, is to be given his own observational show, Robert's Web, which Allen describes as being "like TV Burp for the internet".

Allen pulls a piece of paper out of his pocket to show how serious Channel 4 and its new chief executive, David Abraham, are about comedy. A yearly spend of £11m in 2009, generating 24 hours of comedy programming, will grow to an annual budget of £20.25m next year and 57 hours of television. "It's basically doubling in the space of two years."

The biggest symbol of that extra commitment will be the British Comedy Awards, which will be filmed at the Indigo at the O2 Centre in London in January. Although Jonathan Ross will still host the event, the coverage will be extended from 90 minutes to two hours. "Before, it felt a bit like a corporate event with the telly people slapping each other on the back," Allen says. "We wanted to do a show with more performance, where it's a bit more risky and things will hopefully go terribly wrong and it will be a bit more amusing for the viewer." In the week ahead of the show, Bill Bailey will present five hour-long profiles of some of the biggest stars in British comedy, with Steve Coogan and Simon Pegg among those on Allen's wish list.

Then in the summer, a separate awards show, the British Comedy Awards off the Box, will celebrate the best in live stand-up, podcasts, blogs and tweets. Allen and the awards' organisers hope to set up a Bafta-style academy that will take the voting procedure away from broadcasters and provide bursaries for rising talent.

It's an ambitious programme. Allen, the Channel 4 comedy king, never did stand-up himself because he was "too painfully tortured", he says with a broad smile. Let's hope he's still laughing on his second anniversary in the post. Let's hope we all are.