Unión Juárez is a town and municipality in the Mexican state of Chiapas in southern Mexico. The majority of the population in the municipality is Mam people that preserves the Mam traditions and Mam language. As of 2010, the municipality had a total population of 14,089, up from 13,934 as of 2005. It covers an area of 268.3 km². As of 2010, the town of Unión Juárez had a population of 2,635.