Nicolás Ruíz is a town and municipality in the Mexican state of Chiapas in southern Mexico. As of 2010, the municipality had a total population of 4,317, up from 3,135 as of 2005. It covers an area of 137 km². Other than the town of Nicolás Ruíz, the municipality had 2 localities, neither of which had a population over 1,000.