Orosu (; ) is a rural locality (a selo), the only inhabited locality, and the administrative center of Orosunsky Rural Okrug of Verkhnevilyuysky District in the Sakha Republic, Russia, located from Verkhnevilyuysk, the administrative center of the district. Across the river to the east is Tamalakan. Its population as of the 2010 Census was 730, of whom 344 were male and 386 female, up from 719 as recorded during the 2002 Census.