James Mason

as Richard Francis Heritage

Joyce Howard

as Laura Verity

Tom Walls

as Christopher Child

Phyllis Stanley

as Lily Bernard

Edward Rigby

as Mansel

Ronald Ward

as Carter

David Farrar

as Commander Lippinscott

Karl Stepanek

as Riccardo

Betty Warren

as Fay

Walter Crisham

as Charlie

Jeanne De Casalis

as Lady with Dog

Patricia Medina

as Mary, Manicurist (as Pat Medina)

George Robey

as Pawnbroker

Ronald Chesney

as Max - Mouth Harmonica Player

Peggy Dexter

as Bobby

Finlay Currie

as Merchant Captain

Brefni O'Rorke

as Detective Inspector Burrows

Eric Mason

as Benson - Illusionist

Anthony Holles

as Hotel Hairdresser

Ian Fleming

Kynaston Reeves

as Naval Officer in Charge of Court Martial

Herbert Lomas

as Van Driver

Percy Walsh

as Police Sergeant

Terence de Marney

as Code Expert

Elizabeth Flatau

Charles Victor

as Pub Owner

Robert Sansom

as Petty Officer Bill Grant

Alvar Liddell

as Boothby - Radio Announcer

Anthony Dawson

as 2nd Code Expert

Alf Goddard

as One of Mansel's Tough Friends (uncredited)

David Keir

as Henry (uncredited)

Jack Melford

as Defence Lawyer at Court Martial (uncredited)

Hay Petrie

as Waiter (uncredited)

Leonard Sharp

as Bus Conductor (uncredited)

Dennis Wyndham

as George the Barman (uncredited)