Alasdair Mac Colla Chiotaich MacDhòmhnaill (c. 1610 – 13 November 1647), also known by the English variant of his name Sir Alexander MacDonald, was a military officer best known for his participation in the Wars of the Three Kingdoms, notably the Irish Confederate Wars and Montrose's Royalist campaign in Scotland during 1644-5. A member of the Gaelic gentry of the Clan MacDonald of Dunnyveg, a branch of the Clan Donald active in the Hebrides and Ireland, Mac Colla is particularly notable for the very large number of oral traditions and legends which his life inspired in the Highlands.