Nizhneyansk (; ) is an urban locality (an urban-type settlement) in Ust-Yansky District of the Sakha Republic, Russia, located from Deputatsky, the administrative center of the district, 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 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.