• 
  Richard Alexander

  Prince Barin [Chs. 5-13]
• 
  Earl Askam

  Officer Torch
• 
  George Cleveland

  Professor Hensley
• 
  Buster Crabbe

  Flash Gordon
• 
  Muriel Goodspeed

  Zona [Ch. 4]
• 
  Priscilla Lawson

  Princess Aura
• 
  Jack 'Tiny' Lipson

  King Vultan [Chs. 5-13]
• 
  Theodore Lorch

  High Priest #2 [Chs. 8-11, 13]

• 
  Charles Middleton

  Ming the Merciless
• 
  House Peters Jr.

  Shark Man [Chs. 3-4]
• 
  James Pierce

  Prince Thun [Chs. 2-9, 12-13]
• 
  Jean Rogers (I)

  Dale Arden
• 
  Frank Shannon

  Dr. Alexis Zarkov
• 
  Richard Tucker

  Professor Gordon
• 
  Duke York

  King Kala [Chs. 2-5] (as Duke York Jr.)