Mcwilliam Family History
Mcwilliam Surname Meaning
Scottish and Irish: Anglicized form of Gaelic Mac Uilleim a patronymic from a Gaelicized form of William also Anglicized as Williamson in Scotland.
The name is thought to be mainly Scottish in Ulster though there has been some confusion with McQuillan in County Down.
In Connacht McWilliam was a branch of Burke.
Source: Dictionary of American Family Names 2nd edition, 2022