Medea
Main character of the tragedy, from which it takes its name, Medea is the daughter of King Aeëtes of Colchis (present-day western Georgia). After being rejected by Jason, the Greek hero she helped to get the Golden Fleece, she decides to plot a revenge on him and his betrothed, Creusa, daughter of Creon, king of Corinth, selling to her a poisoned robe as a wedding gift and killing her own sons behind their father's (Jason) eyes.
Jason
Greek hero, leader of the Argonauts in search of the Golden Fleece. He reaches his goal thanks to magic arts and deceptions of Medea, who falls in love with him. But, after having brought her in Corinth, Jason leaves Medea, to contract a new marriage with Creusa, daughter of Creon, king of that town.
Creusa
Princess of Corinth, daughter of the king of the town, Creon. To marry her, Jason abandoned Medea, arousing her wrath. The Colchian sorceress will take revenge on her too, selling a robe poisoned by her as a wedding gift. Creusa and her father die because of the fire broken out by that mantle, impossible to put out with water.
Creon
Creon is the King of Corinth and the new father in law of Jason. He is afraid of Medea, fearing of her revenge on his family after Jason's betrayal. He tries to banish Medea from his land before she does any harm to them.
Chorus
The Chorus is made up of the people of Cornith. They celebrate the wedding of their princess and disregard Medea's feelings of betrayal.