Donald Pleasence

Dr. Hawley Harvey Crippen

Coral Browne

Belle Crippen

Samantha Eggar

Ethel Le Neve

Donald Wolfit

R.D. Muir (as Sir Donald Wolfit)

James Robertson Justice

Captain McKenzie

Geoffrey Toone

Mr. Tobin

Douglas Bradley-Smith

Dr. Pepper

Olga Lindo

Mrs. Clara Arditti

Elspeth March

Mrs. Jackson

Paul Carpenter

Bruce Martin

John Arnatt

Chief Inspector Dew

Oliver Johnston

Lord Chief Justice

John Lee

Harry

Edward Underdown

The Governor

Hamilton Dyce

Dr. Rogers

Basil Henson

Mr. Arditti

Totti Truman Taylor

Miss Curnow

Edward Cast

Harding

Colin Rix

Chemist

Terence Brook

Police Sergeant Outside Courtroom (uncredited)

Eric Dodson

Defence QC Clerk (uncredited)

Max Faulkner

Radio Officer Andrews (uncredited)

Guy Standeven

Ships Steward (uncredited)

John Tatham

Courtroom Spectator (uncredited)