Sayylyk (; , Sayñlñk) is a rural locality (a selo), the only inhabited locality, and the administrative center of Mukuchunsky Rural Okrug of Kobyaysky District in the Sakha Republic, Russia, located from Sangar, the administrative center of the district. Its population as of the 2010 Census was 1,221, up from 1,156 recorded during the 2002 Census.