Monarchies in the Americas

The Commonwealth of Nations, some of whose countries in America are monarchies, including: Antigua and Barbuda, The Bahamas, Belize, Canada, Grenada, Jamaica, Saint Kitts and Nevis, Saint Lucia, Saint Vincent and the Grenadines, and the British Overseas Territories. (Not shown: the Falkland Islands and South Georgia and the South Sandwich Islands in the South Atlantic Ocean).
The Dutch Caribbean islands, under the Monarchy of the Netherlands
  Aruba
  Curaçao
  Sint Maarten
  Caribbean Netherlands
Greenland is a constituent country of the Danish Realm in North America, which has the Danish monarchy

There are 12 monarchies in the Americas, being either sovereign states or self-governing territories that have a monarch as head of state. Each is a constitutional monarchy, wherein the monarch inherits his or her office according to law, usually keeping it until death or abdication, and is bound by laws and customs in the exercise of their powers. Ten of these monarchies are part of the global personal union known as the Commonwealth realms and share Charles III, who resides in the United Kingdom, as king. The other two are the Monarchy of the Netherlands which is used in states of the Dutch Caribbean, and the Monarchy of Denmark which is used in Greenland. As such, none of the monarchies in the Americas have a permanently residing monarch, though the Commonwealth realms each have a resident governor-general to represent King Charles III and perform most of his constitutional duties in his name; and a high commissioner represents the King of Denmark and the Danish government in Greenland. Additionally, each of Canada's 10 provinces functions as a subnational constituent monarchy, with the constitutional powers vested in the King exercised at the provincial level by a lieutenant governor.

Historically, some pre-Columbian societies existed under monarchical forms of government, while others had a decentralised collection of tribal regions under a hereditary chieftain. None of the contemporary monarchies, however, are descended from those pre-colonial royal systems, instead either having their historical roots in European monarchies which colonized the New World beginning in the 15th century.

From that date on, through the Age of Discovery, European colonization brought extensive American territory under the control of Europe's monarchs (although for much of this era, the Dutch Republic was not a monarchy). The majority of these colonies eventually gained independence from their rulers. Some did so via armed conflict with their mother countries, as in the American Revolution and the Latin American wars of independence, usually severing all ties to the overseas monarchies in the process (today, none of the Latin American nations that were former Spanish colonies share a personal union with the Spanish monarchy). Others gained full sovereignty by legislative paths, such as Canada's patriation of its constitution from the United Kingdom. A number of former colonies became republics immediately upon achieving self-governance. Haiti and Brazil formed constitutional monarchies with their own resident monarch, though all eventually became republics, and Mexico had two short-lived Mexican Empires propped up by foreign intervention before returning to a republican form of government.