Alec Guinness
Professor Marcus
Cecil Parker
Claude, alias 'Major Courtney'
Herbert Lom
Louis, alias 'Mr. Harvey'
Peter Sellers
Harry, alias 'Mr. Robinson'
Danny Green
'One-Round', alias 'Mr. Lawson'
Katie Johnson
Mrs. Wilberforce
Jack Warner
The Superintendent
Philip Stainton
The Sergeant
Frankie Howerd
The Barrow Boy
Madge Brindley
Large Lady (uncredited)
Hélène Burls
Hypatia (uncredited)
Kenneth Connor
Cab Driver (uncredited)
Michael Corcoran
Burglar (uncredited)
Harold Goodwin
Parcels Clerk (uncredited)
Fred Griffiths
Junk Man (uncredited)
Lucy Griffiths
Miss Pringle (uncredited)
George Hilsdon
Security Van Driver (uncredited)
Vincent Holman
Station Master (uncredited)
Stratford Johns
Security Guard (uncredited)
Sam Kydd
Second Cab Driver (uncredited)
Edie Martin
Lettice (uncredited)
Jack Melford
Detective (uncredited)
Arthur Mullard
(uncredited)
Ewan Roberts
Constable (uncredited)
George Roderick
Radio Car Policeman (uncredited)
John Rudling
Nervous Man (uncredited)
Leonard Sharp
Pavement Artist (uncredited)
Peter Williams
Detective at Parcels Office (uncredited)
Neil Wilson
Policeman (uncredited)
Phoebe Hodgson
Constance (uncredited)
William Rose
Screenplay
Otto Heller
Director of Photography
Jack Harris
Editor
Alexander Mackendrick
Director
Michael Balcon
Producer
Jimmy O'Connor
Screenplay
Sydney Pearson
Special Effects
Dock Mathieson
Music Director
Hal Mason
Production Supervisor
Tom Pevsner
Assistant Director
Bert Davey
Assistant Art Director
Jack Shampan
Set Designer
Chic Waterson
Camera Operator
Jim Clark
Assistant Editor
Jim Morahan
Art Direction
Anthony Mendleson
Costume Design
Alan Bryce
First Assistant Camera
W. Simpson Robinson
Scenic Artist
David Peers
Unit Production Manager
Alex Garfath
Makeup Artist
Tony Rimmington
Set Designer
Ray Parslow
First Assistant Camera
Herbert Smith
First Assistant Camera
Harry Aldous
Assistant Editor
Norman Dorme
Set Designer
Joan Bridge
Color Timer
Daphne Martin
Hairstylist
Stephen Dalby
Supervising Sound Editor
Felicia Manheim
Continuity
William Rose
Story
Seth Holt
Associate Producer
Leo Wilkins
Sound Recordist
Gordon Stone
Sound Editor
Robin Clarke
Assistant Editor
Tristram Cary
Original Music Composer