Alastair Sim

as Professor Ernst Kronak

Fred Emney

as Sir George Denberry-Baxter

Edward Rigby

as Timmy Tiverton

Oliver Wakefield

as Sir Reginald Foxfield

Patricia Roc

as Hope Ollerton

Annie Esmond

as Lady Foxfield

Marian Spencer

as Lady Shepshod

Olive Sloane

as Daisy Barley

Maire O'Neill

as Mrs. Mitterley

Gus McNaughton

as Ketley

Charles Hawtrey

as Young Orton

Peter Gawthorne

as Major Shiptonthorpe

Aubrey Mallalieu

as Commander Spofforth

G.H. Mulcaster

as Inspector

Wally Patch

as Sam

Horace Kenney

as Walter Shepton

Morris Harvey

as Jim Flagg

Ida Barr

as Katie

Spencer Trevor

as Colonel Hazelhead

Peter Ustinov

as Dr. Bentika

Robert Atkins

as Hassock

Diana Beaumont

as Secretary

Syd Crossley

as Uncle Alfred

A. Bromley Davenport

as Agent

Charles Doe

as Mayor

Alexander Field

as Packles Junior

Ian Fleming

as United Plastics Barrister

Richard George

as Tom Largs

Leopold Glasspoole

as Pelham

Michael Martin Harvey

as Handover

W.T. Holland

David Keir

as Mr. Finningley

Henry B. Longhurst

as Bald-headed Man with Blonde

Eliot Makeham

as Town Clerk

George Merritt

as Police Sergeant

Mignon O'Doherty

as Dr. Buckley

Stan Paskin

as Attendant

Maurice Rhodes

Alan Tomkins

Sam Wilkinson

Joss Ambler

Frank Atkinson

Cecil Bevan

Beckett Bould

Laurence Hanray

Raymond Lovell

Arthur Maude

Billy Merson

Leonard Sharp

as Doorman at 'Dog and Bell'

Robert Brooks Turner

Charles Victor

Jack Vyvyan

as Police Constable

H Victor Weske

Ben Williams