Rutherglen by election, 1964

There was a by-election for the constituency of Rutherglen in the United Kingdom House of Commons on 14 May 1964, not long before the 1964 general election.

It was a Labour gain from Conservative, the candidate was Gregor Mackenzie. Unlike some by-election gains it was held at the next general election and eventually became a fairly safe Labour seat, with Mackenzie as its MP until 1987. The defeated Conservative candidate, Iain Sproat, later served as the MP for Aberdeen South and Harwich. The Scottish National Party decided not to contest the election, even though it was party policy to contest all Scottish by-elections.