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)