Jeremy Scott's new collection for Adidas is as wacky as his catwalk creations says Harriet Walker

I like to just, boom, hit it, and be very succinct," says Jeremy Scott, in his cartoonish but business-like Californian drawl, of the spring/summer 2010 collection that he showed in London last month. Having previously shown in Paris, New York and LA, Scott brought his colourful and comic look to the capital for the first time this season.

And succinct it certainly was, its mission statement clearly laid out from the instant the first model appeared on the catwalk: Flintstones-inspired, Fifties-influenced pieces, from jagged swimsuits – one with a tiger tail dangling from its posterior – via candyfloss-pink biker jackets, to bone-print hoodies and skirts. "The inspiration was, what if Pebbles and Lady Gaga and Debbie Harry got together, did their own girl group, and they were going on tour – how would they look?"

The trio may seem unlikely, but 35-year old Scott is at home with most celebrities, not to mention cartoon characters, having dressed both Lady Gaga and Miss Piggy in the past. The fantasy narrative that he has come up with is also nothing new: previously he has drawn inspiration from Barbie dolls, the host of American TV game show Wheel of Fortune and, incongruously, the US government's energy policies.

His spring/summer 2009 show was entitled "Let Them Eat Gas" and featured Marie Antoinette-style mini-crinis and pompadours, worn with Eighties crop-tops emblazoned with the word "Healthy". "It was President Bush," he says emphatically. "Gas prices go up, when there are huge controlled reserves around the world? It's BS. All that was just setting us up for what was, in my opinion, a French Revolution, and it happened."

Scott stayed in London after his show to launch a pop-up boutique in Selfridges, where his autumn/winter collection for Adidas's Originals by Originals line (ObyO for short) is being sold this month. "In the middle of a huge, worldwide economic recession, my wing shoes debuted and sold out in 24 hours," he points out. "Is it that people have no money to spend? Is it that they don't want anything unusual because they're scaling back? No. It's that they'll die and do whatever it takes to get something inspiring and different."

Scott is wearing the much-coveted trainers when we meet in the lobby of the May Fair Hotel, along with some cropped sequinned jogging bottoms and an oversized trefoil T-shirt from the line. It's fair to say that he and his mohawk stand out a little from the bespoke suits and glitzy wives dotted on nearby sofas, but there is a specific London street scene that Scott's clothes tap into perfectly. "It's wonderful, how much effort everyone puts into getting dressed up here," he says of the capital. "I love it, this panache for fashion." It's no surprise then that Scott chose the London scenester Pixie Geldof to model in his show. "She's a new-age punk rock star," he says delightedly.

The youthful crowd that Scott dresses enjoy his streetwear aesthetic and sense of humour. "I have my fans and customers; I know who I'm speaking to and they're the ones who are egging me on, wanting more and pushing it further," Scott admits, with some affection. "I'm very welcoming but I understand that not everyone's going to love it."

He certainly divides opinion in the fashion world: there are those who think he is a genius, and others who think he is a joke. Karl Lagerfeld once told the French newspaper Le Monde that Scott was the only designer who could follow him at Chanel, while another critic once wrote, "Only someone from another planet would finance the monstrosities on [his] catwalk". Lucky, then, that Scott's designs are fairly out of this world.

It's also fortunate that his clothes are financially rewarding beyond many designers' wildest dreams; Scott clothes most of the MTV set, creating pieces for the aforementioned Lady Gaga, as well as Kylie Minogue, Beth Ditto and MIA. He designed Madonna's bustled fencing kit for her "Die Another Day" video, as well as Britney's futuristic air-hostess dress – electric blue with swooping shoulder yokes and a cutaway back – from the video to her hit "Toxic". "For those who feel it's weird, well, eff off," Scott retorts. "I'm dressing every popstar worth their weight in gold already, plus a bunch I don't even know about, and the clothes are selling out."

His defensiveness is perhaps a product of the way he has been received, by the American fashion industry in particular. Having dreamt of being a designer for most of his childhood, Scott was crushed when, aged 18, he received a rejection letter from New York's prestigious Fashion Institute of Technology that claimed he lacked "originality, creativity and artistic ability". He remembers weeping after reading it, but flew from his hometown in Missouri to attend the Pratt Institute in Brooklyn instead.

After graduating, he went to Paris to find an internship but was spotted in the street by Jean Paul Gaultier, who admired his look, and ended up with his own TV show, where he pulled in higher viewing figures on the French channel Canal Plus than the Spice Girls ever did.

His first show was in Paris in 1997, where he stayed for 11 years, before trying New York, LA and now London. The French are known for their classic style, but they embraced Scott's playful, individual vision. "It's fun, it's exciting" he reasons. "Not everyone can relate to some weird, obscure reference from German art. You know what I mean?" Only too well, some might say, at the often po-faced and complex references that some designers wheel out as inspirations. "Po-faced?" asks Scott during our interview. "I've been learning lots of new things here, like 'Dusted and done' and 'Bob's your uncle'. But who's Bob?"

He takes a democratic and realistic view of the industry. "I feel like a lot of fashion does itself a disservice," he says. "It's way too expensive, it's way too conceptual, and it's unattainable." Preaching the virtues of "wearability", having once dressed models in one-legged trousers and dresses with vast, clam-shaped ruffs, is perhaps a little suspect, but people do wear his clothes: you need only look around his shows to note a sea of phosphorescent fans, gently glowing in Scott's signature techno colours and clashing prints. "It's about being sincere, not élite. At the show, I wouldn't deny a seat to someone who has been supportive of me just because they're not well-known, or they're young, or they're on the second row at Prada."

With so much of his work inspired by retro Americana, Scott is a designer truly influenced by his country's lifestyle and casual aesthetic, but it is in Paris and London that he has been best received. Most Americans don't seem to "get" his jokes, although the hip young things certainly do. "I think so much of New York fashion is about fitting into this commercial, Seventh Avenue thing, but so many of those people have been failures – look at Isaac Mizrahi. It's a very insular, fake kind of world," he says bluntly.

And yet, the Council of Fashion Designers of America nominated him for Best Young Designer in 1999. "They just wanted my name to verify that they're still with it," he says, not quite snapping – because his voice is too gentle for that – but making it clear that this was not something he ever set much store by.

"I think my line with Adidas is a shot in the arm to all that," he declares, as he mimes injecting his own bicep, "because it's completely affordable. It's mass-manufactured, but it has the fantasy and the integrity of my designs. And, you know," he pauses and shrugs apologetically, "It's not just shit."

Meeting Jeremy Scott is like watching one of his shows: he broadcasts his message loud and clear, but with a charm and sassiness that means you can't help but like it. Dusted and done, as he has recently learned to say.

ObyO for Adidas is available now.