McAllister (surname) McAllister (surname) McAllister is a surname from Scotland and Ireland that originates from the Gaelic name Mac Alasdair, meaning son of God. Alasdair is the Gaelic form of the first name Alexander. The Mc Alisters for the greater part owe their ancestry to the Scottish clan of the Mac Donalds. The name is derived from the personal name Alexander. The Mc Alisters arrived in Ulster as Gallowglasses at the invitation of the MacDonnell's. Today the greatest numbers of the name are to be found in counties Antrim, Londonderry, Fermanagh, and Dublin, otherwise the name is widely dispersed. The McAllister surname
Eolais mac Biobhsach manuscripts going back almost two hundred years. O'Donovan claimed the family name ( "descendent of Eolais") is still found anglicised as "Olus" or "Olis". two instances of the surname corrupted as "Oelase" and "Olase", are found in the Irish Fiants for Leinster. The surname must be very rare. Eolais mac Biobhsach Eolais "mac Biobhsach" (alias " "knowledge", anglicized "Wallis", "Olis" or "Olus" ) was a chieftain of 10th century Gaelic Ireland. He is noted as the first "full chieftain of Conmaicne Réin". His descendants, "the Muintir Eolais", expanded into the territory of present day south county Leitrim, and parts of