Iole was the daughter of the king of Oechalia, Eurytus, in Greek mythology. When she came of age to get married, her father organised an archery contest; the person that would beat Eurytus in archery would be allowed to marry Iole. However, no one managed to win at the contest until Heracles decided to participate. He managed to do a perfect score, beating Eurytus and his sons, all of them masters of archery. When it was time for Heracles to claim Iole as his prize, though, Eurytus annulled the contest, fearing that Heracles might kill his daughter and any children they might have in the future, just like he had done with his first wife Megara when he fell into madness by Hera.
Iphitus, son of Eurytus, told Heracles he would help him, and the hero accepted; however, he later went into a fit of madness again and killed Iphitus. Heracles left the city and married Deianira, forgetting shortly about Iole. However, he returned to Oechalia with an army, during which Iole unsuccessfully tried to escape. She was taken by Heracles as his lover. The love Heracles had for Iole eventually led to his death; his wife Deianira, fearing Heracles would abandon her, unknowingly gave him the Shirt of Nessus, a shirt smeared with the toxic blood of the centaur Nessus, leading the hero to his death.