The Guarani are a group of culturally-related indigenous peoples of South America. They are distinguished from the related Tupi by their use of the Guarani language. The traditional range of the Guarani people is in what is now Paraguay between the Paraná River and lower Paraguay River, the Misiones Province of Argentina, southern Brazil once as far east as Rio de Janeiro, and parts of Uruguay and Bolivia.

The Tupi people, a subdivision of the Tupi-Guarani linguistic families, were one of the largest groups of indigenous peoples in Brazil before its colonization. Scholars believe that while they first settled in the Amazon rainforest, from about 2,900 years ago the Tupi started to migrate southward and gradually occupied the Atlantic coast of Southeast Brazil.