Colin James Barnett is an Australian former 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 premier of Western Australia is the head of government of the state of Western Australia. The role of premier at a state level is similar to the role of the prime minister of Australia at a federal level. The premier leads the executive branch of the Government of Western Australia and is accountable to the Parliament of Western Australia. The premier is appointed by the governor of Western Australia. By convention, the governor appoints as premier whoever has the support of the majority of the Western Australian Legislative Assembly, the lower house of the Parliament of Western Australia. In practice, this means that the premier is the leader of the political party or group of parties with a majority of seats in the Legislative Assembly. Since Western Australia achieved self-governance in 1890, there have been 31 premiers. Roger Cook is the current premier, having been appointed to the position on 8 June 2023.