The name Gilliland in Ireland is derived from the native Gaelic Mac Giolla Fhaolain Sept of County Sligo although the name is now mostly found in Ulster Province. This Sept name was also anglicized as MacLellan. The name was also brought to the country by settlers who arrived into Ulster, especially during the seventeenth century.

Origen: Escocés. The Gilliland surname is a reduced Anglicized form of the Gaelic Mac Gille Fhaoláin, which means "son of the servant of St Faolán." First found in Midlothian, where they were seated from very ancient times, some say well before the Norman Conquest and the arrival of Duke William at Hastings in 1066 A.D.

Variantes: Gilliland, Gilleland, Gillieland, Gillsland, Gilsland, Gillesland, Gillerlaine, Gillerland, Gillisland, Gillan, Gillander, Gilander y otros.