| En Name: | Nizhneyansk |
| Ru Name: | Нижнеянск |
| Loc Name1: | Нижнеянскай |
| Loc Lang1: | Yakut |
| Coordinates: | 71.4333°N 140°W |
| Map Label Position: | bottom |
| Federal Subject: | Sakha Republic |
| Adm District Jur: | Ust-Yansky District |
| Adm Selsoviet Jur: | Settlement of Nizhneyansk |
| Adm Selsoviet Type: | Settlement |
| Adm Ctr Of: | Settlement of Nizhneyansk |
| Inhabloc Cat: | Urban-type settlement |
| Mun District Jur: | Ust-Yansky Municipal District |
| Urban Settlement Jur: | Nizhneyansk Urban Settlement |
| Mun Admctr Of: | Nizhneyansk Urban Settlement |
| Pop 2010Census: | 391 |
| Established Date: | 1940s |
| Current Cat Date: | 1958 |
| Postal Codes: | 678562 |
| Dialing Codes: | 841166 |
| Bodystyle: | width:23.5em; |
| Nizhneyansk population | |
| Label1: | 2010 Census |
| Data1: | 391 |
| Label2: | 2002 Census |
| Data2: | 701 |
| Label3: | 1989 Census |
| Data3: | 2,502 |
| Label4: | 1979 Census |
| Data4: | 2,164 |
Nizhneyansk (ru|Нижнея́нск; sah|Нижнеянскай|translit=Nijneyanskay) is an urban locality (an urban-type settlement) in Ust-Yansky District of the Sakha Republic, Russia, located 602km (374miles) from Deputatsky, the administrative center of the district,[1] in the Yana River delta. As of the 2010 Census, its population was 391.
It was founded in the 1940s and was granted urban-type settlement status in 1958.
Within the framework of administrative divisions, the urban-type settlement of Nizhneyansk[2] is incorporated within Ust-Yansky District as the Settlement of Nizhneyansk. As a municipal division, the Settlement of Nizhneyansk is incorporated within Ust-Yansky Municipal District as Nizhneyansk Urban Settlement.[3]