Family History and Genealogy Resources by Surname
McMillan Surname Origin
(Origin Scottish) From the personal name Coinneach meaning comely
Source: An Etymological Dictionary of Family and Christian Names With an Essay on their Derivation and Import; Arthur, William, M.A.; New York, NY: Sheldon, Blake, Bleeker & CO., 1857.
McMillan Surname Meaning and Family Facts
There is more to McMillan family history than the origin of your surname:
A McMillan Family History Thought:
What is past is prologue.