Old Tupi, Ancient Tupi or Classical Tupi is an extinct Tupian language which was spoken by the aboriginal Tupi people of Brazil, mostly those who inhabited coastal regions in South and Southeast Brazil. It belongs to the Tupi–Guarani language family, and has a written history spanning the 16th, 17th, and early 18th centuries. In the early colonial period, Tupi was used as a lingua franca throughout Brazil by Europeans and aboriginal Americans, and had literary usage, but it was later suppressed almost to extinction. Today, only one modern descendant is living, the Nheengatu language.
The names Old Tupi or classical Tupi are used for the language in English and by modern scholars (it is referred to as tupi antigo in Portuguese), but native speakers called it variously ñeengatú "the good language", ñeendyba "common language", abáñeenga "human language", in Old Tupi, or, in Portuguese, língua geral "general language", língua geral amazônica "Amazonian general language", língua brasílica "Brazilian language".
Old Tupi was first spoken by the Tupinambá people, who lived under cultural and social conditions very unlike those found in Europe. It is quite different from Indo-European languages in phonology, morphology, and grammar, but it was adopted by many Luso-Brazilians born in Brazil as a lingua franca known as Língua Geral.
It belonged to the Tupi–Guarani language family, which stood out among other South American languages for the vast territory it covered. Until the 16th century, these languages were found throughout nearly the entirety of the Brazilian coast, from Pará to Santa Catarina, and the Río de la Plata basin. Today, Tupi languages are still heard in Brazil (states of Maranhão, Pará, Amapá, Amazonas, Mato Grosso, Mato Grosso do Sul, Goiás, São Paulo, Paraná, Santa Catarina, Rio Grande do Sul, Rio de Janeiro, and Espírito Santo), as well as in French Guiana, Venezuela, Colombia, Peru, Bolivia, Paraguay, and Argentina.