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.

Western Australia is a state of Australia occupying the western third of the land area of Australia, excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. With a total land area of 2,527,013 square kilometres (975,685 sq mi), Western Australia is Australia's largest state as well as the second-largest subdivision of any country on Earth, surpassed only by the Sakha Republic in eastern Russia. As of 2021, the state has 2.76 million inhabitants—11 percent of the national total. The vast majority live in the south-west corner; 79 percent of the population lives in the Perth area, leaving the remainder of the state sparsely populated.