Under the Australian Constitution, Western Australia ceded legislative and judicial supremacy to the Commonwealth, but retained powers in all matters not in conflict with the Commonwealth.

Legislative power rests with the Parliament of Western Australia, which consists of King Charles III, represented by the Governor of Western Australia, and the two Houses, the Western Australian Legislative Council (the upper house) and the Western Australian Legislative Assembly (the lower house).

[2] The Governor, as representative of the Crown, is the formal repository of power, which is exercised by him or her on the advice of the Premier of Western Australia and the Cabinet.

The Premier and Ministers are appointed by the Governor, and hold office by virtue of their ability to command the support of a majority of members of the Legislative Assembly.

As of 6 November 2023[update], the following individuals serve as government ministers, at the pleasure of the King, represented by the Governor of Western Australia.