Will Rogers
Hank Martin
William Farnum
King Arthur / Inventor
Frank Albertson
Emile le Poulet / Clarence
Maureen O'Sullivan
Alisande / Woman in Mansion
Brandon Hurst
Merlin / Doctor in Mansion
Myrna Loy
Queen Morgan le Fay / Evil Sister in Mansion
Mitchell Harris
Sagramor / Butler in Mansion
Stanley Blystone
King's Knight (uncredited)
Heinie Conklin
Sneezing Man at Radio Station (uncredited)
Louise Emmons
Old Hag in Dungeon (uncredited)