The Green Wing star will play a British comedy writer, with Meet Joe Black's Claire Forlani as his wife and co-writer, in the BBC/Showtime project, written by Friends creator David Crane.
Stephen revealed: "It's about two British writers, a husband and wife team and they've had a really successful show over here, won all the Baftas.
"It's set in an English boarding school and it stars a headmaster, who's a bit of an Ian McKellen or Derek Jakobi type, and then it's bought by this network in America who insist they cast Matt Le Blanc - so it's what happens when these English writers hit LA TV cultures."
The Free Agents star feels the show is a good blend of both American and British comedy.
He said: "They have written very well, because there's really only two Brits in it, me and Claire Forlani who plays my wife. It's about what happens when Brits end up in America and are totally bewildered by the Hollywood system and it's sort of a satire on LA, but it's very funny. I'm really excited about it."
Stephen is currently starring in British independent comedy Beyond The Pole, about two friends who set out on the first Carbon Neutral, Vegetarian, And Organic expedition to the North Pole. The film is produced by and co-stars Helen Baxendale and is directed by her husband David L Williams. True Blood's Alexander Skarsgard is also among the cast.
:: Beyond The Pole is showing at London's Apollo Piccadilly from March 5-12 and is touring UK cinemas.