As of 2010, the municipality had a total population of 3,792,[1] up from 3,132 as of 2005.[2] It covers an area of 221.1 km².
As of 2010, the town of Osumacinta had a population of 2,023.[1] Other than the town of Osumacinta, the municipality had 15 localities, none of which had a population over 1,000.[1]
^"Osumacinta". Enciclopedia de los Municipios de México. Instituto Nacional para el Federalismo y el Desarrollo Municipal Gobierno del Estado de Chiapas. Retrieved August 2, 2008.