This name comes from the Gaelic Gillelosa, the Servant of Jesus. It was common at one time in Badenoch, where the Macphersons of Invereshie were known as the Sliochd Gillies, descended from one Gillies Macpherson, who lived in the reign of Alexander III. A Gillies witnessed a charter by David I to the Abbey of Holyrood in 1128, and another, “M. filius Gilise”, a confirmation of a charter of Malcolm IV to the Abbey of Scone in 1164. This surname is common also in the Outer Isles. Owing to its derivation it has been much in use as a Christian name in the Highlands, when it is usually Englished as Elias. The spelling in the rest of Scotland varies between Gillies and Gilles.
Gillies Dress Ancient