A by-election was held in the state electoral district of Cootamundra on 14 October 2017. The by-election was triggered by the resignation of Katrina Hodgkinson (National). The by-election was won by Steph Cooke for the National Party on preferences. The Nationals suffered a 20% swing on first preference votes and 10% on a two-party basis. The by-election was held on the same day as by-elections in Blacktown and Murray.