The Great St. Trinian's Train Robbery is a British comedy film, directed by Frank Launder and Sidney Gilliat, written by Sidney and Leslie Gilliat, and released on 4 April 1966. It is the last of the original series of films based on the St Trinian's School set of images and comics, and the only one to be produced in colour. The film stars a selection of actors from previous films in the series, including George Cole, Richard Wattis, Eric Barker, Michael Ripper, and Raymond Huntley, alongside Frankie Howerd, Reg Varney, Dora Bryan, and the voice of Stratford Johns.

The film's story focuses on St Trinian's becoming caught up in a train robbery, after the gang who conducted it attempts to reclaim their loot from the building that the students and teachers now inhabit. The story itself is based on the actual Great Train Robbery that took place in 1963, and includes numerous parodies of the technocratic ideas of the Harold Wilson government and its support of the comprehensive school system, and spoof elements based upon those from the James Bond spy films of the Sixties.