The monarchy of Australia is a central component of Australia's system of government, by which a hereditary monarch serves as the country's sovereign and head of state. It is a constitutional monarchy, modelled on the Westminster system of parliamentary democracy and responsible government, while incorporating features unique to the Constitution of Australia.
The present monarch is King Charles III, who has reigned since 8 September 2022. The monarch is represented at the federal level by the governor-general (currently Samantha Mostyn), in accordance with the Australian Constitution and letters patent from his mother and predecessor, Queen Elizabeth II. Similarly, in each of the Australian states the monarch is represented by a governor (assisted by a lieutenant-governor; generally the chief justice of the state's supreme court), according to the Australia Act and respective letters patent and state constitutions. In the Northern Territory (which is legally subordinate to the federal government), the monarch is represented by an administrator appointed by the governor-general. The monarch appoints the governor-general on the advice of the prime minister, and appoints the state governors on the advice of the respective premiers. These are the only mandatory constitutional functions of the monarch of Australia.
