Azusa is a city in the San Gabriel Valley region of Los Angeles County, California United States at the foot of the San Gabriel Mountains located 20 miles (32 km) east of downtown Los Angeles.

The Tongva language is an extinct Uto-Aztecan language formerly spoken by the Tongva, a Native American people who have lived in and around modern day Los Angeles for centuries. It has not been a language of everyday conversation since the 1940s. The Gabrielino people now speak English but a few are attempting to revive their language by using it in everyday conversation and ceremonial contexts. Presently, Gabrielino is also being used in language revitalization classes and in some public discussion regarding religious and environmental issues. Tongva is closely related to Serrano. The names of several cities and neighborhoods in Southern California are of Tongva origin, and include Pacoima, Tujunga, Topanga, Azusa, Cahuenga in Cahuenga Pass and Cucamonga in Rancho Cucamonga.