In Gaelic MacPhail means ‘son of Paul’.  First mention of this surname would appear to be the record in ‘The Book of Thanes of Cawdor, 1236-1742’.  The author of this book maintains that a section of the MacPhails spring from the MacKays, and the list of tenants on the Reay estates about 1678 certainly shows that a number of MacPhails were among them.  The Seil-Phaill of Sir Robert Gordon appear to have been MacKays descended from Paul, son of Neil MacNeil MacKay, the latter a brother of Angus Dubh in 1411.  

The name is a common one around Ardchattan and several MacPhails were among the Fencible men enrolled in Glen Lyon by the Duke of Atholl in 1706.  However, it is said that those of the name MacPhail split into two branches, and have two different origins.  Those from the North, who have no blood connections at all with the more Southerly families are to be held as a sept of the MacKays and descend from one Paul Mac’intire, the son of the Wolf, Lord of Strathcarron and Strathoykell who, from his fastness on the Kyle of Sutherland, was famous for his two origins: those thirled to Clan Chattan spring from a priest, Sir Duncan MacPhail, who lived under Duncan, 11th Chief of the Clan Chattan and the other branch came from among the Can Cameron, of which they were considered a sept, but later they appear to have merged with the neighbouring Clan Chattan.