Alexander S. MacMillan (October 31, 1870 – August 7, 1955) was a Nova Scotia politician and businessman, the 13th premier of Nova Scotia, from 1940 to 1945. MacMillan was born in Upper South River in Antigonish County. He made his fortune in lumbering and construction before being made chairman of the Nova Scotia Highways Board in 1920 and serving briefly as minister of highways in 1925. He was a member of Nova Scotia's appointed upper house, the Legislative Council from 1925 until 1928 when he won a seat in the Nova Scotia House of Assembly as a Liberal. He again became minister of highways in 1933. In 1940, when Premier Angus L. Macdonald went to Ottawa to serve in the wartime cabinet of William Lyon Mackenzie King, MacMillan became premier in his place. He retired as premier and from po