According to the United States Census Bureau, the CDP has a total area of 7.7square miles (20.0Square kilometers), all of it land. Zapata is a census-designated place (CDP) in and the county seat of Zapata County, Texas, United States. The population was 5,089 at the 2010 census. As an unincorporated community, Zapata has no municipal government but like all 254 Texas counties has four elected county commissioners chosen by single-member districts and a countywide elected administrative judge. Zapata was named for Colonel Jose Antonio de Zapata, the revolutionary commander who served in the cavalry of the Republic of the Rio Grande, of which the town was a part.