Marie Curie
Greer Garson
Pierre Curie
Walter Pidgeon
Reporter
Van Johnson
Irene Curie - Age 5
Margaret O'Brien
Narration Spoken By (voice)
James Hilton
Tall Woman (uncredited)
Mariska Aldrich
Man at Accident (uncredited)
Tony Carson
Swedish Queen (uncredited)
Ruth Cherrington
Lecturer (voice) (uncredited)
Ray Collins
Professor (uncredited)
Guy D'Ennery
Cart Driver (uncredited)
George Davis
Harold De Becker
Eugene Curie
Henry Travers
Assistant Tailor (uncredited)
Franz Dorfler
Woman at Accident (uncredited)
Justine Duney
Tay Dunn
William Edmunds
Board Member (uncredited)
Nestor Eristoff
Al Ferguson
Edward Fielding
Prof. Constant (voice) (uncredited)
Howard Freeman
Perot Granddaughter (uncredited)
Linda Lee Gates
Marie Louise Gates
Professor Jean Perot
Albert Bassermann
Lucille (uncredited)
Lisa Golm
Seamstress (uncredited)
Ilka Grüning
Professor Roget (uncredited)
Lumsden Hare
Son (uncredited)
Teddy Infuhr
James Kirkwood
Isabel La Mal
Bit Part (uncredited)
Gene Lockhart
Businessman (uncredited)
Miles Mander
Singing Professor (uncredited)
George Meader
Master Michaud (uncredited)
Dickie Meyers
David Le Gros
Robert Walker
Wedding Guest (uncredited)
Noel Mills
Photographer (uncredited)
Leo Mostovoy
Dr. Bladh (uncredited)
Alan Napier
President of Businessman's Board (uncredited)
Moroni Olsen
María Pagés
Eve at 18 Months (uncredited)
Gigi Perreau
Monsieur Michaud (uncredited)
Francis Pierlot
Nita Pike
Nurse (uncredited)
Dorothy Raye
Madame Michaud (uncredited)
Almira Sessions
Lord Kelvin
C. Aubrey Smith
Arthur Shields
King Oscar (uncredited)
Wyndham Standing
Driver (uncredited)
Ray Teal
Charles Trowbridge
Proud Papa (uncredited)
Michael Visaroff
Jewelry Salesman (uncredited)
Marek Windheim
Frederick Worlock
Doctor (uncredited)
Eustace Wyatt
Madame Eugene Curie
May Whitty
President of University
Victor Francen
Madame Perot
Elsa Bassermann
Dr. Becquerel
Reginald Owen
Director
Mervyn LeRoy
Producer
Sidney Franklin
Costume Supervisor
Irene
Costume Design
Screenplay
Paul Osborn
Music
Herbert Stothart
Art Direction
Cedric Gibbons
Hans Rameau
Writer
Ève Curie
Executive Producer
E.J. Mannix
Director of Photography
Joseph Ruttenberg
Editor
Harold F. Kress