Sweden is a constitutional monarchy, which means that HM The King is the country's Head of State and his duties are regulated by law. The fact that Sweden should have a king or a queen regnant as its head of state is established in the Instrument of Government – one of the kingdom's constitutional laws.

The monarchy of Sweden is centred on the monarchical head of state of Sweden, by law a constitutional and hereditary monarchy with a parliamentary system. There have been kings in what now is the Kingdom of Sweden for more than a millennium.

Sweden occupies the greater part of the Scandinavian Peninsula in northern Europe. It has a 1,000-year-long continuous history as a sovereign state, but its territorial expanse changed often until 1809. Today Sweden is a constitutional monarchy with a well-established parliamentary democracy that dates from 1917.

Sweden is a highly developed country ranked seventh in the Human Development Index, it is a constitutional monarchy and a parliamentary democracy, with legislative power vested in the 349-member unicameral Riksdag. It is a unitary state, divided into 21 counties and 290 municipalities.

Sweden has continuously been a monarchy since the country's consolidation in the Viking Age and early Middle Ages, for over a thousand years. The incumbent royal dynasty of Sweden is the House of Bernadotte, established on the throne in 1818.