Donald Mackay, MacKay, or McKay may refer to:
Donald Mackay, 5th of Strathnaver (died 1370), chief of the ancient Clan Mackay
Donald Mackay, 11th of Strathnaver (died 1550), chief of the ancient Clan Mackay
Donald Mackay, 1st Lord Reay (1591–1649), Scottish peer and soldier
Donald Mackay (fur trader) (1753–1833), Canadian trader with the North West Company Donald Mackay (Royal Navy officer) (1780–1850), British admiral Donald McKay (1810–1880), Canadian-American shipbuilder (1938) one of the first C2 ships Donald McKay (politician) (1836–1895), Canadian politician Donald McKay (scout) (1836–1899), American scout, actor, and spokesman Donald Mackay, 11th Lord Reay (1839–1921), Dutch-born British administrator and Liberal politician Donald McDonald Mackay (1845–1904), Australian politician Donald George Mackay (1870–1958), Australian explorer and long-distance cyclist Donald McKay (footballer) (fl. 1890s), Scottish footballer Donald W. MacKay (1874–1952), Canadian politician Donald Morrison MacKay (1889–1953), Canadian politician Donald Brenham McKay, former mayor of Tampa, Florida Don McKay (politician) (1908–1988), New Zealand politician Donald Hugh Mackay (1914–1979), mayor of Calgary, Alberta Donald A. Mackay (1914–2005), illustrator Donald MacCrimmon MacKay (1922–1987), Scottish physicist Donald Mackay (anti-drugs campaigner) (1933–1977), Australian politician and anti-drugs campaigner Donald Mackay (scientist) (1936–2023), Scottish-born Canadian scientist of environmental chemistry Don Mackay (born 1940), Scottish football player Donald Mackay, Baron Mackay of Drumadoon (1946–2018), Scottish judge Donald Mackay (medical doctor) (died 1981) Donald Mackay-Coghill (born 1941), South African cricketer