Sirionó (Mbia Cheë; also written as Mbya, Siriono) is a Tupian (Tupi–Guarani, Subgroup II) language spoken by about 400 Sirionó people (50 are monolingual) and 120 Yuqui 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.

Sirionó has phonemic contrasts between front, central, and back, close and mid vowels, i.e.