The Parliament of Western Australia is the bicameral legislature of the Australian state of Western Australia, which constitutes the legislative branch of the state's political system. The parliament consists of the King, the Legislative Council and the Legislative Assembly. The two Houses of Parliament sit in Parliament House in the state capital, Perth.

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. Western Australia is Australia's largest state, with a total land area of 2,527,013 square kilometres (975,685 sq mi). It is the second-largest country subdivision in the world, surpassed only by Russia's Sakha Republic. 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.