For the genus of grass skipper butterflies, see Oeonus (butterfly).

In Greek mythology, Oeonus was a son of Licymnius who accompanied Heracles. He was killed in Sparta in Hercules's company. Hercules had promised Licymmius that he would bring back his son, and so, when Oeonus died, Hercules burned his body and took the ashes back to the father. This is supposed to be the origin of the Greek practice of cremation.