The monarchy of Papua New Guinea is a system of government in which a hereditary monarch is the sovereign and head of state of Papua New Guinea.
Although the person of the sovereign is equally shared with other independent countries within the Commonwealth of Nations, each country's monarchy is separate and legally distinct. As a result, the monarch is officially titled the King of Papua New Guinea and, in this capacity, he, his consort, and other members of the Royal Family undertake public and private functions domestically and abroad as representatives of the Papua New Guinean state.
King Charles III acceded to the throne on 9 September 2022 upon the death of his mother, Queen Elizabeth II, becoming the Head of State of a number of realms of the Crown, including Papua New Guinea.
In Papua New Guinea King Charles III is styled: "His Majesty Charles the Third, King of Papua New Guinea and His other Realms and Territories, Head of the Commonwealth" (thus omitting the "Defender of the Faith" title used in the United Kingdom and some other realms).
The monarch, besides reigning in Papua New Guinea, separately serves as monarch for a number of other Commonwealth countries known as Commonwealth realms. This developed from the former colonial relationship of these countries to Great Britain, but they are now independent of each other and are legally distinct.