The Government of Western Australia is the Australian state democratic administrative authority of Western Australia. It is also commonly referred to as the WA Government or the Western Australian Government. The Government of Western Australia, a parliamentary constitutional monarchy, was formed in 1890 as prescribed in its Constitution, as amended from time to time. Since the Federation of Australia in 1901, Western Australia has been a state of the Commonwealth of Australia, and the Constitution of Australia regulates its relationship with the Commonwealth. 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.

The Constitution of Australia is the fundamental law that governs the political structure of Australia. It is a written constitution, that establishes the country as a federation under a constitutional monarchy governed with a parliamentary system. Its eight chapters sets down the structure and powers of the three constituent parts of the federal level of government: the Parliament, the executive government and the judicature.