In Greek mythology, Eurytion referred to three different people.
One was the King of Phthia and father of Antigone. In Phthia, Peleus was purified by Eurytion for the murder of Phocus and married Antigone, Eurytion's daughter. Peleus accidentally killed Eurytion during the hunt for the Calydonian Boar and fled Phthia.
Son of Ares and the Hesperid Erytheia, who bore him "beside the silver-rooted boundless waters of the river Tartessus, in the hollow of a rock. He was the guardian of the cattle of Geryon and was killed by Heracles.
He lived on Erytheia, a mythical island far to the west, Geryon was the owner of huge herds of cattle, and they were protected by the herdsman Eurythion and the two-headed watch-dog Orthrus.
When Heracles reached Erytheia, no sooner had he landed he was confronted by the two-headed dog Orthrus, with one huge blow from his olive-wood club Heracles killed the watch-dog.
Eurythion the herdsman came to assist Orthrus, but Heracles overcame the attack in the same manner.