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)