Donald Mackay, 11th of Strathnaver (died 1550), was the eleventh chief of the ancient Clan Mackay, a Scottish clan of the Scottish Highlands.
Donald Mackay was the second eldest son of Iye Roy Mackay, 10th of Strathnaver, and his wife who was the daughter of Norman, son of Patrick O'Beolan of Carloway, Lewis. Donald’s elder brother, John Mackay, 11th of Strathnaver, died in 1529 without legitimate male issue and therefore Donald was able to succeed him as chief of the Clan Mackay.
In around 1529 Donald Mackay of Strathnaver assisted the Master of Forbes (of Clan Forbes) and Sir John Campbell of Cawdor during a feud in which Alexander Seaton of Meldrum was killed. Historian Angus Mackay states that it is with interest that at this time the Mackays and Forbeses who claim to have sprung from the same kindred stock in the distant past, are found acting in concert. It was probably for the death of Seaton of Meldrum that Mackay obtained a pardon for himself and his Strathnaver clansmen dated 26 July, 1536. In July 1537, the Master of Forbes and his sister-in-law, Janet Douglas, Lady Glamis, sister of Douglas, Earl of Angus, were both executed for conspiring against the king. Associated with Lady Glamis was one Alexander Makay who was sentenced to be banished from all parts of Scotland except for the county of Aberdeen. Sir John Campbell of Cawdor, brother of the Earl of Argyll, who had been associated with the Mackays and Forbeses in the killing of Seaton, also killed Maclean of Duart (chief of Clan Maclean) in bed in about 1529. Maclean had left his wife, Lady Elizabeth Campbell, exposed to certain death on a lonely sea-girt isle. The killing of Maclean resulted in a prolonged feud between the Macleans and the Campbells in which the Mackays of Kintyre suffered severely at the hands of the Macleans and it appears that the Mackays supported the Campbells during the feud.