The Belles of St Trinian's is a 1954 British comedy film, directed by Frank Launder, co-written by Launder and Sidney Gilliat, and starring Alastair Sim, Joyce Grenfell, George Cole, Hermione Baddeley. Inspired by British cartoonist Ronald Searle's St Trinian's School comic strips, the film focuses on the lives of the students and teachers of the fictional school, dealing with attempts to shut them down while their headmistress faces issues with financial troubles, which culminates in the students thwarting a scheme involving a racehorse.

St Trinian's is a British gag cartoon comic strip series, created and drawn by Ronald Searle from 1946 until 1952. The cartoons all centre on a boarding school for girls, where the teachers are sadists and the girls are juvenile delinquents. The series was Searle's most famous work and inspired a popular series of comedy films.