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 as

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 as

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)