The electoral results for the district of Penrith was dominated by the Labor party on four elections since 1973 up until 2010 after which Stuart Ayres of the Liberal party lost in the 2010 elections.
Ayres took the previously safe Labor seat on a 25.7-point swingthe largest swing against a sitting government in New South Wales history. Ayres was elected at the Penrith state by-election on 19 June 2010, receiving 66.3% of the two-party-preferred vote. Stuart Ayres 2010present Liberal 
Ayres was elected at the Penrith state by-election on 19 June 2010, receiving 66.3% of the two-party-preferred vote. 
