Mischa Barton has signed up to star in the St Trinian's remake.

The 21-year-old actress, who made her name in US drama series The OC, will appear alongside Rupert Everett, Girls Aloud, Colin Firth and Lily Cole in the British comedy.

St Trinian's is currently being filmed in and around London. It is being directed by Oliver Parker, who helmed the 2002 remake of The Importance of Being Earnest, and Barnaby Thomas.

St Trinian's began life as a series of drawings by English cartoonist Ronald Searle. The first film in the series - The Belles of St Trinian's - was released in 1954 and spawned three sequels.