The Gilliland surname is a reduced Anglicized form of the Irish Gaelic Mac Gille Fhaoláin, which means "son of the servant of St. Faolán". This group has been established for male participants with the surname Gilliland and other closely related spellings. The objective is to determine relationships that might be difficult to prove using traditional methods of genealogical research. So far, we have discovered through DNA testing that there were two distinct groups of Gillilands that came to America early and the two groups are not closely related. These two groups have been labeled Group 1 and Group 2. DNA testing will help determine which group your Gilliland ancestor belongs to.