Douglas Marmaduke Caston (September 17, 1917 – June 26, 1996) was a Canadian newspaper publisher and served as a federal politician from 1967 until 1968.
Caston ran for a seat in the House of Commons of Canada in a by-election on November 6, 1967.
Parliament would be dissolved a year later and Caston ran for re-election in the new Rocky Mountain electoral district as Jasper—Edson was abolished.
An unusual event happened in that election as the Progressive Conservatives had 2 endorsed candidates running under their party banner for that district.
Sulatycky would win and Caston was defeated finishing third behind the other Progressive Conservative candidate Hugh Gourlay.