Quilliam
Quilliam—This name is the anglicised form of McWilliams, the Dumbarton Co. sept. The Scottish forms of the name are M'Killiams, M'Illiams, Williamson, and M'Quilliams (Mac Uilliam).
Alphabetical Index of Anglicised Surnames in Ireland
See also Woulfe’s Irish Names and Surnames
… and O'Hart's Irish Pedigrees