Jason
Medea
Acastus
Argos
Zeus
Hermes / Priest
Pelias
King Aeetes
Hera
Hylas
Phineas
Phalerus
Hercules
Dmitrius (uncredited)
Guard in Palace (uncredited)
Polydeuces (uncredited)
Lynceus (uncredited)
Triton (uncredited)
Medea (voice) (uncredited)
Castor (uncredited)
Eupaemus (uncredited)
Skeleton (uncredited)
Briseis (uncredited)
Jason (voice) (uncredited)