Dennis Price as Louis Mazzini / His Father

Alec Guinness as The D'Ascoyne Family: The Duke / The Banker / The Parson / The General / The Admiral / Young Ascoyne / Young Henry / Lady Agatha

Joan Greenwood as Sibella

Valerie Hobson as Edith D'Ascoyne

Audrey Fildes as Mama

Miles Malleson as The Hangman

Clive Morton as The Prison Governor

John Penrose as Lionel Holland

Cecil Ramage as Crown Counsel

Hugh Griffith as Lord High Steward

John Salew as Mr. Perkins

Eric Messiter as Inspector Burgoyne

Lyn Evans as The Farmer

Barbara Leake as The Schoolmistress

Peggy Ann Clifford as Maud Redpole

Anne Valery as The Girl in the Punt

Arthur Lowe as The Reporter

Peter Gawthorne as First Lord Delivering Verdict (uncredited)

Molly Hamley-Clifford as Lady Redpole (uncredited)

Leslie Handford as Gamekeeper Hoskins (uncredited)

Cavan Malone as Young Graham (uncredited)

Jeremy Spenser as Young Louis (uncredited)

Carol White as Young Sibella (uncredited)

Laurence Naismith as Warder in Jail (uncredited)

Gordon Phillott as Clerk of Parliament (uncredited)

Richard Wattis as Defence Counsel (uncredited)

Harold Young as Captain (uncredited)