Donald Mackay, MacKay, or McKay may refer to:
Politics and government
Donald McKay (politician) (1836–1895), Canadian politician Donald Mackay, 11th Lord Reay (1839–1921), Dutch-born British administrator and Liberal politician Donald McDonald Mackay (1845–1904), Australian politician
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 Mackay (anti-drugs campaigner) (1933–1977), Australian politician and anti-drugs campaigner Donald Mackay, Baron Mackay of Drumadoon (1946–2018), Scottish judge
Sports
Donald George Mackay (1870–1958), Australian explorer and long-distance cyclist Donald McKay (footballer) (fl. 1890s), Scottish footballer Don Mackay (born 1940), Scottish football player Donald Mackay-Coghill (born 1941), South African cricketer
Other people 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 (scout) (1836–1899), American scout, actor, and spokesman Donald MacKay (architect) (), Scottish-American architect
Donald Cameron MacKay (1906–1979), Canadian maritime artist Donald A. Mackay (1914–2005), American illustrator Donald McKay (RAF officer) (1917–1959), British flying ace of the Second World War Donald MacCrimmon MacKay (1922–1987), Scottish physicist Donald Mackay (scientist) (1936–2023), Scottish-born Canadian scientist of environmental chemistry Donald Mackay (medical doctor) (died 1981)