Donald Mackay, 1st Lord Reay, 14th of Strathnaver (March 1591 – February 1649) was a Scottish soldier and member of Parliament. He played a prominent role in the Thirty Years' War, raising a regiment of 3,000 men, which served in both the Danish and Swedish forces. He was later an unwilling Covenanter. He was the fourteenth chief of Clan Mackay, a Highland Scottish clan.