Bryant Haliday as The Great Vorelli

William Sylvester as Mark English

Yvonne Romain as Marianne Horn

Sandra Dorne as Magda Gardinas

Karl Stepanek as Dr. Heller

Francis de Wolff as Dr. Keisling

Nora Nicholson as Aunt Eva

Alan Gifford as Bob Garrett

David Charlesworth as Hugo Novik

Sadie Corre as Hugo the Dummy

Lorenza Colville as Mercedes

Trixie Dallas as Miss Penton

Guy Deghy as Hans

Heidi Erich as Grace

Philip Ray as Uncle Walter

Ella Tracey as Louisa, secretary

Margaret Durnell as Countess

John Tatum as Charity Ball Guest (uncredited)