Paisley South by election, 1990

The Paisley South by-election, 1990 was a parliamentary by-election held on 29 November 1990 for the British House of Commons constituency of Paisley South, in the town of Paisley, Scotland.

It was caused by the death of the constituency's Labour Member of Parliament (MP) Norman Buchan.

As in the by-election in the neighbouring seat of Paisley North held on the same day, the SNP saw a healthy increase in their share of the vote, but not enough to win, and the Labour Party retained the seat, with Gordon McMaster being their successful candidate.

The by-election was the first parliamentary election to take place under the premiership of Conservative prime minister John Major, who had succeeded Margaret Thatcher as prime minister just two days earlier. Although the change of leader sparked an almost instant upswing in Conservative support (which had been declining for the previous 18 months largely due to the poll tax) and ultimately saw them win the general election in April 1992, the Tories failed to take advantage of this by-election, polling at a mere 13.4% and failing to alter the political climate in a traditional Labour stronghold.