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.
| Actor | Role |
|---|---|
 Buster CrabbeFlash Gordon | Flash Gordon |
 Jean RogersDale Arden | Dale Arden |
 Frank ShannonDr. Zarkov | Dr. Zarkov |
 Charles MiddletonEmperor Ming | Emperor Ming |
 Beatrice RobertsQueen Azura | Queen Azura |
 Donald KerrHappy Hapgood | Happy Hapgood |
 Richard AlexanderPrince Barin | Prince Barin |
 C. Montague ShawClay King | Clay King |
 Wheeler OakmanTarnak | Tarnak |
 Kane RichmondStratosled Pilot (Talgon's Brother) | Stratosled Pilot (Talgon's Brother) |
 Warner RichmondZandar | Zandar |
 Anthony WardeKing Turan of the Forest People | King Turan of the Forest People |
 Kenne DuncanAirdrome Captain | Airdrome Captain |
 Jack MulhallBomber Captain | Bomber Captain |
 Lane ChandlerFlight Commander | Flight Commander |
| BBen LewisProfessor | Professor |