The 1990 Maylands state by-election was a by-election for the seat of Maylands in the Legislative Assembly of Western Australia held on 26 May 1990. It was triggered by the resignation of Peter Dowding (the sitting Labor member and former premier) on 26 April 1990. The Labor Party retained Maylands at the election, albeit with a reduced majority. Judy Edwards, a general practitioner based in Mount Lawley, secured 55.57 percent of the two-party-preferred vote. Edwards became only the second woman to win election to the Parliament of Western Australia at a by-election, after May Holman in 1925. The election occurred on the same day as the 1990 Fremantle state by-election.