In Greek mythology, Eteocles (/ᵻˈtiːəkliːz/; Ancient Greek: Ἐτεοκλῆς) was a king of Thebes, the son of Oedipus and either Jocasta or Euryganeia. The name is from earlier *Etewoklewes (Ἐτεϝοκλέϝες), meaning "truly glorious". Tawagalawas is thought to be the Hittite rendition of the name. Oedipus killed his father Laius and married his mother without knowing his relationship to either. When the relationship was revealed, he was expelled from Thebes. The rule passed to his sons Eteocles and Polynices. However, because of a curse from their father, the two brothers did not share the rule peacefully. Eteocles was succeeded by his uncle, Creon.

Oedipus's curse

In the Thebaid, the brothers were cursed by their father for their disrespect towards him on two occasions. The first of these occurred when they served him using the silver table of Cadmus and a golden cup, which he had forbidden. The brothers then sent him the haunch of a sacrificed animal, rather than the shoulder, which he deserved. Enraged, Oedipus prayed to Zeus that the brothers would die by each other's hands. However, in Sophocles's Oedipus at Colonus, Oedipus desired to stay in Thebes but was expelled by Creon. His sons argued over the throne, but Eteocles gained the support of the Thebans and expelled Polynices, who went to Oedipus to ask for his blessing to retake the city, but instead was cursed to die by his brother's hand.

In Greek mythology, Eteocles was a king of Orchomenus. The local tradition concerning him is preserved in Pausanias' Description of Greece, and runs as follows.

Eteocles was the son of Andreus (himself son of the river-god Peneus) and Euippe, daughter of Leucon, and successor to his father's throne. Alternately, he was called son of the river god Cephissus (hence referred to by the patronymic Cephisiades in some poetical texts according to Pausanias). He was credited with having founded two tribes (phylae), one of which received the name Cephisias after his possible father, and the other one was named after himself. He assigned a little of his land to Almus, son of Sisyphus, who was believed to have given his name to the village Olmonas ("Almones" was the alleged original form of its name). Eteocles was also said to have been the first to offer sacrifices to the Charites, and to have recognized three as the true number of the goddesses.

The mythological connection between Eteocles and the Charites is confirmed by the account of Theocritus, who refers to the Charites as "divine daughters of Eteocles". Strabo also credits Eteocles with founding the temple of the Charites, and mentions that Eteocles "was the first to display both wealth and power; for he honored these goddesses either because he was successful in receiving graces, or in giving them, or both."