Columbia's King of the Wild Horses is a remake of the silent Hal Roach western feature of the same name -- and with the same "star," Rex the Wonder Horse, in the lead. Most of the story involves the romantic triangle between rogue stallion Rex, the gorgeous mare Lady, and villainous black steed Marquis.
| Actor | Role |
|---|---|
 William JanneyTwo Feathers | Two Feathers |
 Dorothy ApplebyNapeeta | Napeeta |
 Wallace MacDonaldGorman | Gorman |
 RexRex (as Rex the Wonder Horse) | Rex (as Rex the Wonder Horse) |
| LLady the HorseThe Mare | The Mare |
| MMarquis the HorseRex's Rival | Rex's Rival |
 Harry SemelsJohn Foster | John Foster |
| FFord WestDr. Anderson | Dr. Anderson |
 Art MixHaley | Haley |
 Charles Le MoyneHenchman (uncredited) | Henchman (uncredited) |