- Language: Ersu
- Alternate names: 爾蘇語
- Language code: ers
- Language family: Sino-Tibetan, Tibeto-Burman, Northeastern Tibeto-Burman, Ersuish (SIL classification)
- Number of speakers: ~13000
- Vulnerability: Threatened
- Script: Ersu Shaba Picture Writing, no longer in use, limited usage, used in religious ceremonies.
Most officially classified within Tibetan nationality; some as Han nationality. Traditional religion.
The Ethnologue Ersu [ers] contains three mutually unintelligible languages, i.e. Duoxu /do³³-ɕu³³-na³¹/ (central Ersu), Ersu /ə́˞súxò/ (eastern Ersu), and Lisu /lîzûhû/ or /lŷzûhû/ (western Ersu). Note that is entry only contains information on Ersu (eastern Ersu).Documentation project “Ersu and Xumi: Comparative and Cross-Varietal Documentation of Highly Endangered Languages of South-West China” by CNRS-CRLAO (France), Sichuan Minorities Institute, and Xichang College, supported by the Endangered Languages Documentation Programme (grant number MPD0257), 2013-2016.