The surname McMillian originated in Scotland during the late medieval period. It is a variant of the name MacMillan, derived from the Gaelic "mac" meaning "son of" and the personal name "Milian" or "Gillan". The name Milian likely originated from the Latin name "Aemilianus", meaning "favored one".
The earliest recorded bearer of the name was Gilbert McMilian, who was documented in the records of Whithorn, Wigtownshire in 1453. The name was also found in the Ragman Rolls of 1296, which recorded those who swore allegiance to King Edward I of England. Notable bearers in these early records include John McMylane, also spelled McMyllan, who was a resident of Ayrshire.
The McMillians were prominent in the Scottish Highlands, particularly in the regions of Argyll and the Isles. Their presence can be traced back to the 13th century, when they were followers of the powerful Clan Donald. In the 16th century, the McMillians were supporters of the MacDonalds of Dunyeg during the clan conflicts in the region.
The name McMillian can also be found in early records from Ireland, where it was often anglicized as McMullion or McMullin. One of the earliest recorded bearers in Ireland was John McMullin, who was listed in the Fiants of the County of Wexford in 1605.
Notable individuals with the surname McMillian throughout history include:
1. Sir Duncan McMillan (c. 1480-1552), a Scottish nobleman and supporter of the House of Argyll.
2. Angus McMillan (1810-1865), an Australian explorer and pastoralist, known for his expeditions in Gippsland, Victoria.
3. Charles McMillan (1856-1926), an American businessman and co-founder of the Washburn-Crosby Company, which later became General Mills.
4. Lachlan McMillan (1895-1971), a Scottish-born Australian architect who designed many notable buildings in Sydney.
5. Celestine McMillan (1918-2002), an American baseball player who played for the Brooklyn Dodgers in the 1940s.
The name McMillian has also been associated with various place names, including McMillan Island in British Columbia, Canada, and McMillan Park in Washington, D.C., which was named after Senator James McMillan (1838-1902).