Directed by Ford Beebe
Robert F. Hill - (as Robert Hill)
Frederick Stephani - (first serial footage - uncredited)

Writing credits (in alphabetical order)
Herbert Dalmas - story and screenplay
Wyndham Gittens - story and screenplay
Norman S. Hall - story and screenplay
Alex Raymond - comic strip
Ray Trampe - story and screenplay

Cast (in credits order)
Buster Crabbe - Flash Gordon
Jean Rogers - Dale Arden
Charles Middleton - Emperor Ming
Frank Shannon - Dr. Zarkov
Beatrice Roberts - Queen Azura
Donald Kerr - Happy Hapgood
Richard Alexander - Prince Barin
C. Montague Shaw - Clay King (as Montague Shaw)
Wheeler Oakman - Tarnak
Kenne Duncan - Airdrome Captain (as Kenneth Duncan)
Warner P. Richmond - Zandar (as Warner Richmond)
Jack Mulhall - Bomber captain
Lane Chandler - Flight commander
Anthony Warde - King Turan of the Forest People
Ben Lewis - Professor

rest of cast listed alphabetically:
Wheaton Chambers - Professor (scenes deleted)
Kane Richmond - Pilot captain
Earl Askam - Officer Torch, in Flashbacks [Chs. 6, 10, 14] (uncredited)
Hooper Atchley - Dr. Dunord (uncredited)
James Blaine - Prof. Richter [Chs. 1,9] (uncredited)
Thomas Carr - Capt. Rama, of the Forest People [Chs. 6-7, 10] (uncredited)
George Cleveland - Prof. Hensley (uncredited)
George DeNormand - Martian soldier (uncredited)
Earl Douglas - Martian soldier (uncredited)
James Eagles - High Priest of Kalu (uncredited)
Al Ferguson - Soldier (uncredited)
Jerry Frank - Stratosled co-pilot (uncredited)
Jack Gardner - Temple priest (uncredited)
Herbert Holcombe - Martian soldier (uncredited)
Reed Howes - Stratosled pilot (uncredited)
Fred Kohler Jr. - Soldier (uncredited)
Priscilla Lawson - Princess Aura, in flashback [Chs. 6, 10, 14] (uncredited)
Jack 'Tiny' Lipson - King Vultan, in flashback [Ch. 10] (uncredited)
Louis Merrill - Bit part (uncredited)
Eddie Parker - Martian soldier (uncredited)
James Pierce - Prince Thun, in flashback [Chs. 6, 10] (uncredited)
Stanley Price - Lab worker turned to clay [Ch. 1] (uncredited)
Charles Sherlock - Palace televisor operator (uncredited)
Edwin Stanley - Gen. Rankin [Chs. 1, 9] (uncredited)
Tom Steele - Martian soldier (uncredited)
Glenn Strange - Ming's soldier, in flashback [Ch. 6] (uncredited)
Ray Turner - Zarkov's servant [Ch. 1] (uncredited)
Bud Wolfe - Martian soldier (uncredited)