The Calchaquí were a tribe of South American Indians of the Diaguita group, now extinct, who formerly occupied northern Argentina. Stone and other remains prove them to have reached a high degree of civilization. Under the leadership of Juan Calchaquí they offered a vigorous resistance to the first Spanish colonists coming from Chile.
Their language, known as Cacán, became extinct in the mid-17th century or beginning of 18th century. Its genetic classification remains unclear. The language was supposedly documented by the Jesuit Alonso de Bárcena, but the manuscript is lost.
Friedrich Ratzel in The History of Mankind reported in 1896 that among the Calchaquis of Northern Argentina is found pottery painted with line drawings of birds, reptiles, and human faces, which remind one of Peruvian and Malay work. The Calchaqui people had bronze age technology.