Oeneus was a king of the area of Calydon in Greek mythology, son of King Porthaon and Queen Euryte. He married Althaea, with whom he had a number of children, including Deianeira, Meleager, Toxeus, Clymenus, Periphas, Gorge, Eurymede, Perimede and Melanippe.
When Artemis sent a huge boar, called the Calydonian Boar, in his lands to ravage them because he had forgotten to honour the goddess, Oeneus asked his son Meleager to gather a party of heroes to kill the creature. The party consisted of Meleager, Atalanta, and Meleager's uncles; Atalanta played a major role in successfully hunting down and killing the boar. When the time came to give the boar's skin as a prize, Meleager gave it to Atalanta, despite the protests of his uncles who believed it should be theirs by right of birth. Meleager got furious and in the argument that broke out, he killed his uncles. This eventually marked Meleager's doom as well, when his mother found out what happened.
Oeneus' nephews usurped the throne of Calydon, but after a while, the reigns returned to Oeneus, helped by his grandson Diomedes. Oeneus died either due to old age or he was killed by his nephews. He was buried in Argos by Diomedes.