Mid Londonderry was a county constituency comprising the central part of County Londonderry. It was created in 1929, when the House of Commons (Method of Voting and Redistribution of Seats) Act (Northern Ireland) 1929 introduced first-past-the-post elections throughout Northern Ireland. It was one of five single-member constituencies replacing the former five-member Londonderry constituency. The constituency survived unchanged, returning one member of Parliament until the Parliament of Northern Ireland was temporarily suspended in 1972, and then formally abolished in 1973.