Donald McDonald MacKay (c. 1845 – 30 January 1904) was an Australian pastoralist and politician who was a member of the Legislative Council of Western Australia from 1896 to 1902, representing North Province.

MacKay left for Western Australia in 1869, and went to the Pilbara, where he developed a pastoral lease on the Maitland River.

With his brother, Roderick MacKay, he later developed Mundabullangana Station on the Yule River.

MacKay married (Emily) Charlotte Vincent on 21 February 1893 at Scots Church, Fremantle,[4] with whom he had three children.

[5] The author Catherine Edith Macauley Martin was his youngest sister, and it may be noted that the subject of this article, Donald McDonald MacKay, had a brother (third son of Samuel) Donald Mackay (1832 – 24 December 1901),[6] sheep grazier of Mundabullangana,[7] Yule and Benmore stations.