O'Friel is a Donegal name. In Irish it is O'Firghil (from Feargal); it is pronounced, and often written, O'Frighil, i.e. in English phonetic O'Freel. The sept has a distinguished origin, being descended from Eoghan, brother of St. Columcille (Fr. John Ryan, S.J. has pointed out that the chief point of interest about the O'Friels is that they are nearest in blood to St. Colmcille, for they alone are in the direct line from his brother), and the leading family were hereditary coarbs of Kilmacrenan, County Donegal. The Chief of the Name possessed the hereditary right of inaugurating O'Donnell as lord of Ticonnell. Not being a powerful or numerous sept they do not appear very frequently in the national records; wherever they do they are of Tirconnell (Donegal). The records of the Diocese of Raphoe have many references to distinguished ecclesiastics of the name, both has O'Friel and Friel, including one Bishop Florence or Feargal O'Friel (death 1299). Awley O'Friel was one of the many clergy from Raphoe and Derry who went to Iona - he was elected Abbot of Iona in 1203.

Statistics relating to the modern distribution of the population indicate the name is seldom met with outside County Donegal and contiguous areas.