The monarchy of Antigua and Barbuda is a system of government in which a hereditary monarch is the sovereign and head of state of Antigua and Barbuda. The current Antiguan and Barbudan monarch and head of state, since 8 September 2022, is King Charles III. As sovereign, he is the personal embodiment of the Crown of Antigua and Barbuda. Although the person of the sovereign is equally shared with 14 other independent countries within the Commonwealth of Nations, each country's monarchy is separate and legally distinct. As a result, the current monarch is officially titled King of Antigua and Barbuda and, in this capacity, he and other members of the Royal Family undertake public and private functions domestically and abroad as representatives of Antigua and Barbuda. However, the King is the only member of the Royal Family with any constitutional role.

Antigua and Barbuda is a sovereign island country in the Caribbean. It lies at the conjuncture of the Caribbean Sea and the Atlantic Ocean in the Leeward Islands part of the Lesser Antilles.