The National Assembly and the King of Saint Christopher and Nevis jointly make up the legislature of Saint Kitts and Nevis.

The monarchy of Saint Kitts and Nevis is a system of government in which a hereditary monarch is the sovereign and head of state of Saint Kitts and Nevis. The current monarch of Saint Kitts and Nevis, since 8 September 2022, is King Charles III. As sovereign, he is the personal embodiment of the Crown of Saint Kitts and Nevis. 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 Saint Christopher and Nevis and, in this capacity, he and other members of the royal family undertake public and private functions domestically and abroad as representatives of Saint Kitts and Nevis. However, the King is the only member of the royal family with any constitutional role.