|Native to||United States (California)|
|ISO 639-3||(included in cst)|
Chochenyo (also called Chocheño and East Bay Costanoan) was the spoken language of the Chochenyo people. Chochenyo is one of the Costanoan dialects in the Utian family. Linguistically, Chochenyo, Tamyen and Ramaytush are thought to have been dialects of a single language.
The Muwekma Ohlone Tribe, which (as of 2007) is petitioning for U.S. federal recognition, has made efforts to revive the language. As of 2004, "the Chochenyo database being developed by the tribe ... [contained] from 1,000 to 2,000 basic words."  By 2009, many students were able to carry on conversations in the Chochenyo language. Through both successful word formation, as well as extending documented words, the Chochenyo dictionary has grown significantly throughout the early 21st Century. During the canonization of Saint Junípero Serra on September 23, 2015, the first reading at Mass was read in Chochenyo by Vincent Medina, a Muwekma Ohlone tribal member.
- Hammarström, Harald; Forkel, Robert; Haspelmath, Martin; Bank, Sebastian, eds. (2016). "East Bay [Costanoan]". Glottolog 2.7. Jena: Max Planck Institute for the Science of Human History.
- Ron Russell (2007-03-28). "The Little Tribe That Could. As descendants of San Francisco's aboriginal people, the Muwekma Ohlone Indian tribe seldom gets much respect. But that could be about to change.". SF Weekly. Retrieved 2012-07-24.
- Kathleen Maclay (2004-06-04). "06.04.2004 - Conferences focus on saving native languages". UC Berkeley News. Retrieved 2012-07-23.
- Chochenyo revitalization – language at UCB "Faith in Words" 2004
- "Ethnologue report for language code: cst". Retrieved 2012-07-24.