When a deadly Nitron ray strikes Earth, Flash Gordon and his friends travel to Mars to battle Ming the Merciless and his new ally Queen Azura.
Buster Crabbe
as Flash Gordon
Jean Rogers
as Dale Arden
Frank Shannon
as Dr. Zarkov
Charles Middleton
as Emperor Ming
Beatrice Roberts
as Queen Azura
Donald Kerr
as Happy Hapgood
Richard Alexander
as Prince Barin
C. Montague Shaw
as Clay King
Wheeler Oakman
as Tarnak
Kane Richmond
as Stratosled Pilot (Talgon's Brother)
Warner Richmond
as Zandar
Anthony Warde
as King Turan of the Forest People