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.