Colin James Barnett (born 15 July 1950) is a former Australian politician who was the 29th Premier of Western Australia. He concurrently served as the state's Treasurer at several points during his tenure and had previously held various other portfolios in Western Australia's Court–Cowan Ministry. The Liberals were defeated at the 2017 election, and WA Labor's Mark McGowan succeeded Barnett as Premier. On 15 December 2017, Barnett announced his intention to resign from politics, which he did on 5 February 2018.