| En Name: | Ust-Yansk |
| Ru Name: | Усть-Янск |
| Other Name: | Усуйаана |
| Other Lang: | Sakha |
| Coordinates: | 70.9167°N 162°W |
| Map Label Position: | bottom |
| Federal Subject: | Sakha Republic |
| Adm District Jur: | Ust-Yansky District |
| Adm Selsoviet Jur: | Ust-Yansky Rural Okrug |
| Adm Selsoviet Type: | Rural okrug |
| Adm Ctr Of: | Ust-Yansky Rural Okrug |
| Inhabloc Cat: | Rural locality |
| Inhabloc Type: | Selo |
| Mun District Jur: | Ust-Yansky Municipal District |
| Mun District Jur Ref: | [1] |
| Rural Settlement Jur: | Ust-Yansky Rural Settlement |
| Mun Admctr Of: | Ust-Yansky Rural Settlement |
| Pop 2010Census: | 317 |
| Postal Codes: | 678563 |
Ust-Yansk (Russian: Усть-Янск; Yakut: Усуйаана, Usuyaana) is a rural locality (a selo), the only inhabited locality, and the administrative center of Ust-Yansky Rural Okrug of Ust-Yansky District in the Sakha Republic, Russia, located 486km (302miles) from Deputatsky, the administrative center of the district.[2] Its population as of the 2010 Census was 317,[3] down from 341 recorded during the 2002 Census.