Very numerous: most areas, especially Ulster & Connacht. Ir. Ó h-Airt, Art, a very popular personal name meaning "bear". Originally a Meath sept of the Southern Uí Néill, they were expelled to Connacht. Some Hartes in Ulster may be of English origin. IF.
Harte: líonmhar gach áird, Connachta & Ulaidh go sonrach. Clann a ruaigeadh ón Mhí go Sligeach ag na Normannaigh. Sloinne Sasanach, leis, i bPlandáil Uladh. SI.
fairly rare: Sligo-Fermanagh-Monaghan-Louth. Ir. Ó h-Airt from first name Art, meaning bear. A sept of Meath, dispossessed at the Invasion, they settled in Sligo. See also Harte. IF.