The fourth form monsters' latest trick is their best ever – they have burned down St Trinian’s school! As the girls stand trial, the police breathe a sigh of relief, but miraculously the judge's infatuation with a student means the school is freed. For the authorities, it means a new reign of terror as the girls of St Trinian’s regroup with gleeful anticipation.

Cecil Parker
as Professor Canford

George Cole
as 'Flash' Harry Cuthbert Edwards

Joyce Grenfell
as Sergeant Ruby Gates

Eric Barker
as Culpepper-Brown

Thorley Walters
as Butters

Irene Handl
as Miss Harker-Parker

Dennis Price
as Gore Blackwood

Sidney James
as Alphonse O'Reilly

Julie Alexander
as Rosalie Dawn

Lloyd Lamble
as Superintendent Samuel Kemp-Bird