Monarchism is the advocacy of the system of monarchy or monarchical rule. A monarchist is an individual who supports this form of government independently of any specific monarch, whereas one who supports a particular monarch is a royalist. Conversely, the opposition to monarchical rule is referred to as republicanism.

A monarchy is a form of government in which a person, the monarch, is head of state for life or until abdication. The political legitimacy and authority of the monarch may vary from restricted and largely symbolic, to fully autocratic, and can span across executive, legislative, and judicial domains.