The Kawaiisu language^[2] is a Uto-Aztecan language spoken by the Kawaiisu people of California.

Kawaiisu is a member of the Southern Numic division of the Uto-Aztecan language family.

The Kawaiisu homeland was bordered by speakers of non-Numic Uto-Aztecan languages: the Kitanemuk to the south spoke Takic, the Tubatulabal to the north spoke Tubatulabal, the Yokuts to the west were non-Uto-Aztecan. Because they shared the Southern Numic language, the Chemehuevi to the east are considered the closest relatives to Kawaiisu.

The remaining Kawaiisu speakers live in the Tehachapi area of California.

In 1994, the language was severely endangered, with perhaps fewer than 20 remaining speakers.^[3]

In 2011, The Kawaiisu Project received the Governor’s Historic Preservation Award for its efforts to document the Kaiwaiisu language and culture, including "the Handbook of the Kawaiisu, language teaching and the Kawaiisu Language and Cultural Center [and] the Kawaiisu exhibit at the Tehachapi Museum."^[4][5] As of 2012, the Kawaiisu Language and Cultural Center offers language classes and DVDs for home learning, as well as training for other groups seeking to create language learning programs and materials.

Kawaiisu is an agglutinative language, in which words use suffix complexes for a variety of purposes with several morphemes strung together.