MacGillis comes from the Gaelic "Gille Iosa,"meaning "Servant of Jesus" and appears as "Mac Gill' Iosa",or more commonly as Gillis, Gillies, MacGillis, or MacGillies.

This name is found especially in Badenoch and in the WesternHighlands and Islands, and more particularly in Morar, on the northwest coastof Scotland.

Gillis is typically considered to be a sept of theMacPherson clan, but given the prevalence of the surname in Morar, and theHebrides, it has a strong association with MacDonell of Glengarry, andMacDonald of Clanranald.

As this surname is not a patronym, it is likely that thereis no single origin or mutual common ancestor (MCA); however, it is likely thatthe project will shed light on the various lineages from Scotland, particularlythose that settled in Ontario, Prince Edward Island, Nova Scotia, Newfoundland,and Cape Breton, as well as Australia, New Zealand, and the United States.