Cagliostro

Orson Welles

— Joseph Balsamo aka Count Cagliostro

Nancy Guild

— Marie Antoinette / Lorenza

Akim Tamiroff

— Gitano

Frank Latimore

— Gilbert de Rezel

Valentina Cortese

— Zoraida

Margot Grahame

— Mme. du Barry

Stephen Bekassy

— Viscount de Montagne

Berry Kroeger

— Alexandre Dumas, Sr.

Gregory Gaye

— Chambord / Monk (as Gregory Gay)

Raymond Burr

— Alexandre Dumas, Jr.

Charles Goldner

— Dr. Franz Anton Mesmer

Lee Kresel

— King Louis XVI / Innkeeper

Robert Atkins

— King Louis XV

Nicholas Bruce

— De Remy

Franco Corsaro

— Chico

Annielo Mele

— Joseph Balsamo as a Child

Ronald Adam

— Court President

Bruce Belfrage

— Crown Prosecutor

Alexander Danaroff

— Dr. Duval / Baron von Minden

Leonardo Scavino

— Gaston / Beniamino Balsamo (as Leon Lenoir)

Tamara Shayne

— Maria Balsamo

Joop van Hulzen

— Minister of Justice

Peter Trent

— Dr. Mesmer's Friend

Giuseppe Varni

— Boehmer

Tatyana Pavlova

— Grieving Mother

Harriet Medin

— (uncredited)

Valentino Bruchi

— (uncredited)

Ludmilla Dudarova

— (uncredited)

Rosina Galli

— (uncredited)

Silvana Mangano

— (uncredited)