Misiones is one of the 23 provinces of Argentina, located in the northeastern corner of the country in the Mesopotamia region. It is surrounded by Paraguay to the northwest, Brazil to the north and east, and Corrientes Province of Argentina to the southwest.

The Misiones plateau includes a part of Brazil across the border. The rocks contain significant quantities of iron which forms a part of the soil, giving it a reddish color. At the center of the plateau rises the Sierra de Misiones, its highest peak, 843 m, near Bernardo de Irigoyen, in the Cerro Rincón.

The subtropical climate has no dry season, which makes Misiones one of the most humid provinces in Argentina. The vegetation is the so called "Selva Misionera". Part of it has been transformed by mankind to implant cultures and ranching. The original biome is protected in Iguazú National Park.