The Belles of St Trinian's is a comedy film set in the fictional St Trinian's School, released in 1954. It and its sequels were inspired by British cartoonist Ronald Searle. Directed by Frank Launder and written by him and Sidney Gilliat, it was the first of a series of five. Alastair Sim stars in a dual role as the headmistress Miss Millicent Fritton and her twin brother Clarence Fritton.