Polyxo ( Ancient Greek: ) is the name of several figures in Greek mythology:
- Polyxo, one of the Hyades.
- Polyxo, a Naiad of the river Nile, presumably one of the daughters of the river-god Nilus. She was one of the wives of Danaus and bore him twelve daughters: Autonoe, Theano, Electra, Cleopatra, Eurydice, Glaucippe, Anthelea, Cleodora, Euippe, Erato, Stygne, and Bryce. They married twelve sons of Aegyptus and Caliadne, Polyxo's sister, and murdered them on their wedding nights.
- Polyxo, mother of Antiope by Nycteus.
- Polyxo, a Lemnian, nurse of Hypsipyle and a seeress. She advised that the Lemnian women conceive children with the Argonauts, as all the men on the island had previously been killed.
- Polyxo, a native of Argos, who married Tlepolemus and fled with him to Rhodes. Together they had a son, whose name is not known. After Tlepolemus was killed in the Trojan War, Polyxo became queen of Rhodes. She received Helen after the latter had been driven out of Sparta by Megapenthes and Nicostratus ( Menelaus, Helen's husband, was already dead by the time). Still, Polyxo regarded Helen as the culprit of Tlepolemus' death and eventually decided to take revenge on her. So when Helen was bathing, several handmaidens in the guise of the Erinyes, sent by Polyxo, seized her and hanged her from a tree. In an alternate version, Menelaus and Helen landed at Rhodes on their way back from Egypt, whereupon Polyxo sent a crowd of armed islanders of both genders against them, hoping to avenge her husband's death on Helen. Menelaus hid Helen away under the deck and had a beautiful servant dressed up as the queen, which resulted in her, and not the real Helen, being killed. Yet another source, which uses the name "Philozoe" rather than "Polyxo", informs that she held funeral games of Tlepolemus; youths competed in them, and the winners were crowned with white poplar leaves.
- Polyxo, mother of Actorion. She came to invite Triopas and Erysichthon to her son's wedding, but Erysichthon's mother had to answer that her own son was not coming, as he had been wounded by a boar during hunt. The truth was that Erysichthon was dealing with the insatiable hunger sent upon him by the angry Demeter.
- Polyxo, a Maenad in the retinue of Dionysus who attempted to kill Lycurgus of Thrace.
- Polyxo, one of the Oceanids.
- Polyxo (or Polyzo), a sister of Meleager.