Fionn Mac Cumhaill

Fionn mac Cumhaill ( /ˈfɪn məˈkuːl/ fin mə-KOOL; ; Old Irish: Find mac Cumail or Umaill), known in English as Finn McCool, was a mythical hunter-warrior of Irish mythology, occurring also in the mythologies of Scotland and the Isle of Man. The stories of Fionn and his followers the Fianna, form the Fenian Cycle (or Fiannaidheacht), much of it purported to be narrated by Fionn's son, the poet Oisín.

"Fionn" is actually a nickname meaning "blond", "fair", "white", or "bright". His childhood name was Deimne ( /ˈdeɪni/; ), literally "sureness" or "certainty", and several legends tell how he gained the nickname when his hair turned prematurely white. The name "Fionn" is related to the Welsh name "Gwyn", as in the mythological figure Gwyn ap Nudd, and to the continental Celtic "Vindos", an epithet for the god Belenus.

The 19th century Irish revolutionary organisation known as the Fenian Brotherhood took its name from these legends. The Scottish name Fingal ( /ˈfɪŋɡəl/) comes from a retelling of these legends in epic form by the 18th century poet James Macpherson.