Lugh or Lug is a figure in Irish mythology. A member of the Tuatha Dé Danann, a group of supernatural beings, Lugh is portrayed as a warrior, a king, a master craftsman and a saviour. He is associated with skill and mastery in multiple disciplines, including the arts. Lugh also has associations with oaths, truth and the law, and therefore with rightful kingship. Lugh is linked with the harvest festival of Lughnasadh, which bears his name. His most common epithets are Lámfada and Samildánach. This has sometimes been anglicised as "Lewy of the Long Hand".

Lughnasadh, Lughnasa or Lúnasa is a Gaelic festival marking the beginning of the harvest season. Historically, it was widely observed throughout Ireland, Scotland and the Isle of Man. Traditionally it is held on 1 August, or about halfway between the summer solstice and autumn equinox. In recent centuries some of the celebrations have shifted to the Sunday nearest this date. Lughnasadh is one of the four Gaelic seasonal festivals, along with Samhain, Imbolc and Beltane. It corresponds to the Welsh Gŵyl Awst and the English Lammas.