William Archibald Mackintosh, CC, CMG, FRSC (May 21, 1895 – December 29, 1970) was a Canadian economist and political scientist, and was the twelfth principal of Queen's University from 1951 until 1961.
He is best known for developing the staple thesis that explains Canadian economic history in terms of a series of exports of staple products – fish, fur, timber, and wheat.
Born in Madoc, Ontario, he received his BA and MA from Queen's in 1916.
During the Second World War, he was an assistant to the Deputy Minister of Finance in Ottawa and later in the Department of Reconstruction and Supply.
In 1967 he was made a Companion of the Order of Canada and received the Innis-Gérin Medal, awarded for a distinguished and sustained contribution to the literature of the social sciences, from the Royal Society of Canada, of which he was a fellow and was president from 1956 to 1957.