Kenneth Connor

Gregory Adams

Charles Hawtrey

Michael Bean

Leslie Phillips

Alistair Grigg

Joan Sims

Sarah Allcock

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

Lorna Henderson

Pianiste

Diane Langton

Schoolgirl

Francesca Annis

Schoolgirl (uncredited)