Yorkshire South West was a European Parliament constituency covering the southern parts of West Yorkshire in England and, at times, part of South Yorkshire. Prior to its uniform adoption of proportional representation in 1999, the United Kingdom used first-past-the-post for the European elections in England, Scotland and Wales. The European Parliament constituencies used under that system were smaller than the later regional constituencies and only had one Member of the European Parliament each. The constituency of Yorkshire South West was one of them.