Donald Alexander Macdonald PC (February 17, 1817 – June 10, 1896) was a Canadian politician.

Macdonald served as a Major in the 4th Battalion, Glengarry Militia, succeeding his brother John as Commanding Officer in 1852.

Donald Alexander Macdonald, P.C., and Lieutenant-Governor of Ontario, 1875–80, married Catherine Fraser, daughter of Colonel the Hon.

), who, was appointed a Commander of the Roman Order of St. Gregory (1875), was knighted by Queen Victoria in 1895, and was called to the Senate of Canada in 1896.

[2] His son Col. Alexander George Fraser Macdonald (1863–1948) was an officer in the Canadian Militia, serving in the 59th Stormont and Glengarry Battalion from 1897 to 1914.