Sint Maarten (Dutch pronunciation: [sɪnt ˈmaːrtə(n)]) is a constituent country of the Kingdom of the Netherlands. It encompasses the southern half of the Caribbean island of Saint Martin, while the northern half of the island constitutes the French overseas collectivity of Saint-Martin. Its capital is Philipsburg.

Before 10 October 2010, Sint Maarten was known as the Island Territory of Sint Maarten (Dutch: Eilandgebied Sint Maarten), and was one of five island territories (Eilandgebieden) that constituted the Netherlands Antilles.

In 1493, during Christopher Columbus' second voyages to the West Indies, upon first sighting the island he named it Isla de San Martín after Saint Martin of Tours because it was 11 November, St. Martin Day. However, though he claimed it as a Spanish territory, Columbus never landed there, and Spain made the settlement of the island a low priority.

The French and Dutch, on the other hand, both coveted the island. While the French wanted to colonize the islands between Trinidad and Bermuda, the Dutch found San Martín a convenient halfway point between their colonies in New Amsterdam (present day New York) and Brazil. With few people inhabiting the island, the Dutch easily founded a settlement there in 1631, erecting Fort Amsterdam as protection from invaders. Jan Claeszen Van Campen became its first governor, and soon thereafter the Dutch East India Company began their salt mining operations. French and British settlements sprang up on the island as well. Taking note of these successful colonies and wanting to maintain their control of the salt trade, the Spanish now found St. Martin much more appealing. The Eighty Years' War which had been raging between Spain and the Netherlands provided further incentive to attack.