The Timaru by-election of 1985 was a by-election for the electorate of Timaru during the term of the 40th New Zealand Parliament. It was triggered by the death of Sir Basil Arthur (who had held the seat since 1962) on 1 May 1985. Sir Basil was Speaker of the House, and had inherited the rank of baronet from his father in 1949. The by-election was held on 15 June 1985 and was won by Maurice McTigue of the National Party with a majority of 1,492 votes.