in Latin America, an Indian community set up under ecclesiastical or royal authority to facilitate colonization. Native peoples, many of whom had lived in small villages or hamlets before contact with Europeans, were forcibly relocated to these new settlements. At reducciones, Jesuit missionaries and other colonial administrators attempted to convert Indians to Christianity and to teach them better farming methods and simple crafts. The Indians lived under a strict regimen and were required to contribute their labour to various agricultural and construction enterprises. Some reducciones were ruled locally by Indian caciques, or chiefs, rather than Europeans.

The best known reducciones were those established by Jesuit missionaries in Paraguay. In the region between the Paraguay and Paraná rivers, and in the Argentine Misiones and Corrientes provinces, between the Paraná and Uruguay rivers, the Jesuits converted as many as hundreds of thousands of Indians between 1610 and 1767; many of these converts lived in reducciones.

The Jesuits tried to preserve their territory from outside interference, especially from Spaniards in search of Indian labourers. After their order was suppressed in 1767, most of their settlements went to ruin; some, however, eventually became cities, such as Encarnación and Villarrica. In Brazil there were similar settlements in and to the south of the São Paulo region.