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

Ronald Adam

Court President

Bruce Belfrage

Crown Prosecutor

Leonardo Scavino

Gaston / Beniamino Balsamo (as Leon Lenoir)

Tamara Shayne

Maria Balsamo

Tatyana Pavlova

Grieving Mother

Harriet Medin

(uncredited)

Ludmilla Dudarova

(uncredited)

Rosina Galli

(uncredited)

Silvana Mangano

(uncredited)