Kysyl-Syr (; , Kñhñl Sññr) is a rural locality (a selo), the only inhabited locality, and the administrative center of Khomustakhsky 1-y Rural Okrug of Namsky District in the Sakha Republic, Russia, located from Namtsy, the administrative center of the district. Its population as of the 2010 Census was 1,502, up from 1,351 recorded during the 2002 Census.