Kenneth Connor
Gregory Adams
Charles Hawtrey
Michael Bean
Leslie Phillips
Alistair Grigg
Kenneth Williams
Edwin Milton
Hattie Jacques
Grace Short
Rosalind Knight
Felicity Wheeler
Cyril Chamberlain
Alf Hudson
Ted Ray
William 'Wakie' Wakefield, the Headmaster
George Howell
Billy Haig - Saboteur
Diana Beevers
Penelope 'Penny' Lee - Saboteur
Jacqueline Lewis
Pat Gordon - Saboteur
Roy Hines
Harry Bird - Saboteur
Carol White
Sheila Dale - Saboteur
Richard O'Sullivan
Robin Stevens - Saboteur
Francesca Annis
Schoolgirl (uncredited)