The Asa (Aasá) language, commonly rendered Aasax, was spoken by the Asa people of Tanzania. The language is extinct; ethnic Assa in northern Tanzania remember only a few words they overheard their elders use, and none have ever used it themselves. Little is known of the language; what is recorded was probably Aasa lexical words used in a register of Maasai, rather like the mixed language Mbugu.
Asa is usually classified as Cushitic, most closely related to Kw'adza. However, it might have retained a non-Cushitic layer from an earlier language shift, and might be best left unclassified.