|Role||Voice type||Premiere cast, 18 April 1682|
|Persée son of Jupiter and Danaë||haute-contre||Louis Gaulard Dumesny|
|Andromède daughter of Céphée||soprano|
|Phinée, brother of Céphée||baritone||François Beaumavielle|
|Mérope, sister of Cassiope||soprano||Marie Le Rochois|
|Phronime, attendant of Virtue|
|Mégathyme, attendant of Virtue|
|Céphée, King of Ethiopia||bass|
|Cassiope, Queen of Ethiopia||mezzo-soprano|
|Amphimédon, an Ethiopian|
|Corite, an Ethiopian|
|Proténor, an Ethiopian|
|Méduse, a Gorgon||tenor|
|Euryale, a Gorgon||tenor, descant above Méduse|
|Sténone, a Gorgon||baritone|
|Idas, a Sailor in Céphée's navy|
|High priest of Hymenée (wedding priest)|
|Triton, Neptune's henchman|
|Followers of Virtue and Fortune, followers of Cassiope, young persons chosen for the games, spectators,
warrior nymphs, infernal deities, phantoms, Ethiopians, Tritons and Nereides, victorious heroes (chorus/ballet)
ACT I: The Palace of King Céphée and Queen Cassiope of Ethiopia
King Céphée expresses the terror his people feel for the snake-haired Mèduse: anyone who looks on her turns to stone. The goddess Juno has sent Mèduse to punish Queen Cassiope for her insolence in comparing her own beauty to that of the goddess. In an effort to appease Juno's wrath, Cassiope has prepared a celebration of games in her honour. We learn that Mérope, the queen's sister, secretly loves Persée. However, Persée loves and is loved by Andromède, the king's daughter. Andromède is betrothed to Phinée, her uncle, who, in an agony of jealousy, accuses her of not returning his love, suspecting that she loves another. Andromède assures him that she will fulfil her duty to love him. As the act ends, we learn that Juno has rejected the sacrifices made in her honour. Messengers arrive with the terrible news that Mèduse has taken more victims.
ACT II: The Palace Gardens
Céphée announces that Persée will fight Mèduse to free Ethiopia of her terror; if successful, he is to have Andromède as his own. Phinée is outraged. Andromède and Mérope confess their mutual love for Persée and pray for his safe return. As Andromède and Persée say farewell, she cannot keep herself from confessing that she loves only him. Mercure assures Persée of the assistance of all the gods (except Juno). A troupe of Cyclops brings Persée a sword forged by Vulcan, Warrior Nymphs bring Pallas's diamond shield, and Fiery Spirits from the underworld present him with the helmet of Pluto.
ACT III: The dwelling of the Gorgons
Once a beautiful woman renowned for her gorgeous hair, Mèduse tells how she was turned into a snake-haired monster by the hand of the goddess Pallas Athena, who was jealous of her. Mercure casts a sleeping spell over Mèduse and the Gorgons, who try but cannot resist the spell. Using Athena's shield as a mirror to avoid gazing on Mèduse, Persée beheads her. Using Pluto's helmet to make himself invisible, Persée flees the wrath of the remaining Gorgons, carrying Mèduse's head.
ACT IV: A rocky seacoast in Ethiopia
The Ethiopians are celebrating and awaiting the victorious Persée on a rocky seacoast. A storm arises, and the sailor Idas enters to announce that the furious Juno, along with Neptune, is determined to sacrifice Andromède to a sea monster. Phinée says that he would rather see Andromède dead than in the arms of his rival, confessing that love has died in his heart. Before the despairing eyes of the king, the Tritons chain Andromède to a rock. At the last moment, Persée flies toward the approaching monster and kills it. The storm ends and the Ethiopians celebrate victory.
ACT V: A reception room prepared for the wedding of Persée and Andromède
A devastated Mérope longs for death, then is joined by Phinée. The two conspire to take revenge on Persée with the help of Juno. As the High Priest begins the wedding ceremony, however, Mérope repents of her treachery and warns Persée that Phinée`s assassins are approaching. The wedding guests flee. In the ensuing battle, Mérope is struck by an arrow and killed. With the help of Juno, the battle goes in Phinée's favour; however, Persée uses the Gorgon's head to turn his enemy to stone.
The scene changes to Venus' palace. Venus descends from the heavens to announce that Juno is appeased and the Ethiopians can now live in peace. While Céphée, Cassiope, Persée and Andromède hover on Mercure's wings, the Ethiopians celebrate with dancing and singing.
A 2004 production by Opera Atelier performed live at the Elgin Theatre under the direction of Marshall Pynkoski and conducted by Hervé Niquet in Toronto is the first home video release of the opera. It features Cyril Auvity (Persée), Marie Lenormand (Andromeda), Stephanie Novacek (Cassiope), Monica Whicher (Mérope), Olivier Laquerre (Céphée/Méduse (the latter transposed from F to E-flat)), Alain Coulombe (Phinée), and Colin Ainsworth (Mercure). The designer was Gérard Gauci and the choreographer was Jeannette Zingg. Marc Stone directed the television production.
- The New Grove French Baroque Masters, ed. Graham Sadler (Macmillan, 1986)
- The Viking Opera Guide ed. Holden (Viking, 1993)
- Le magazine de l'opéra baroque by Jean-Claude Brenac (in French)