Middlesex West was a federal electoral district represented in the House of Commons of Canada from 1867 to 1968. It was located in the province of Ontario. It was created by the British North America Act of 1867 which divided the County of Middlesex into three ridings: Middlesex North, Middlesex West and Middlesex East. The West Riding initially consisted of the Townships of Delaware, Caradoc, Metcalfe, Mosa and Ekfrid, and the Village of Strathroy. The electoral district was abolished in 1966 when it was redistributed between Huron, London West and Middlesex ridings.