Belize ( (listen)) is a Caribbean country on the northeastern coast of Central America. It borders Mexico to the north, the Caribbean Sea to the east, and Guatemala to the west and south. It has an area of 22,970 square kilometres (8,867 sq mi) and a population of 397,621 (2020). Its mainland is about 290 km (180 mi) long and 110 km (68 mi) wide. It is the least populated and least densely populated country in Central America. Its population growth rate of 1.87% per year (2018 estimate) is the second-highest in the region and one of the highest in the Western Hemisphere. Its capital is Belmopan, and its largest city is the namesake city of Belize City.

The Maya civilization spread into the area of Belize between 1500 BCE and 300 CE and flourished until about 1200. European contact began in 1492 when Christopher Columbus sailed along the Gulf of Honduras. European exploration was begun by English settlers in 1638. Spain and Britain both laid claim to the land until Britain defeated the Spanish in the Battle of St. George's Caye (1798). In 1840 it became a British colony known as British Honduras, and a Crown colony in 1862. It achieved its independence from the United Kingdom on 21 September 1981. Belize is the only country in Central America with a monarch as its head of state.

Belize has a diverse society that is composed of many cultures and languages that reflect its rich history. It is the only Central American country where English is the official language, while Belizean Creole is the most widely spoken dialect. Spanish is the second most commonly spoken language, followed by the Mayan languages, German dialects, and Garifuna. Over half the population is multilingual, due to the diverse linguistic backgrounds of the population. It is known for its September Celebrations, its extensive barrier reef coral reefs, and punta music.

Belize's abundance of terrestrial and marine species and its diversity of ecosystems give it a key place in the globally significant Mesoamerican Biological Corridor. It is considered a Central American and Caribbean nation with strong ties to both the American and Caribbean regions. It is a member of the Caribbean Community (CARICOM), the Community of Latin American and Caribbean States (CELAC), and the Central American Integration System (SICA), the only country to hold full membership in all three regional organizations. It is the only mainland Central American country which is a Commonwealth realm, with King Charles III as its monarch and head of state, represented by Governor General Dame Froyla Tzalam.