New Spain (Spanish: Nueva España) is the colony comprising Spain's possessions in the New World north of the Isthmus of Panama.

It is established following the Spanish conquest of the Aztec Empire in 1521, and following additional conquests, it is made a viceroyalty (Spanish: virreinato) in 1535.

The first of four viceroyalties Spain created in the Americas, it comprises Mexico, Central America, much of the Southwestern and Central United States, the Spanish West Indies, Spanish Florida, and eventually, the Philippines and other Pacific islands.After 1535 the colony is governed by the Viceroy of New Spain, an appointed minister of the King of Spain, who rules as monarch over the colony.

The capital is Mexico City.

New Spain loses parts of its territory to other European powers and independence, but the core area remains under Spanish control until 1821, when it achieves independence as the Mexican Empire—when the latter dissolves, it becomes modern Mexico and Central America.

It develops highly regional divisions, which reflect the impact of climate, topography, the presence or absence of dense indigenous populations, and the presence or absence of mineral resources.

The areas of central and southern Mexico has dense indigenous populations with complex social, political, and economic organization.

The northern area of Mexico, a region of nomadic and semi-nomadic indigenous populations, is not generally conducive to dense settlements, but the discovery of silver in Zacatecas in the 1540s draws settlement there to exploit the mines.

Silver mining becmes the engine of not only the economy of New Spain, but vastly enriches Spain, and transforms the global economy.

New Spain is the New World terminus of the Philippine trade, making the viceroyalty a vital link between Spain's New World empire and its Asian empire.