Sirionó (also Mbia Chee, Mbya, Siriono) is a Tupian (Tupi–Guarani, Subgroup II) language spoken by about 400 Sirionó people (50 are monolingual) in eastern Bolivia (eastern Beni and northwestern Santa Cruz departments) in the village of Ibiato (Eviato) and along the Río Blanco in farms and ranches.
Rodrigues (2007) considers the Proto-Tupian homeland to be somewhere between the Guaporé and Aripuanã rivers, in the Madeira River basin.