According to the United States Census Bureau, the city has a total area of 13.2square miles (34Square kilometers), of which, 12.5square miles (32Square kilometers) of it is land and 0.7square miles (1.8Square kilometers) of it (5.09%) is water. Belton is a city in Bell County, Texas, United States. The population was 14,623 at the 2000 census. It is the county seat of Bell County. Belton is part of the KilleenTempleFort Hood Metropolitan Statistical Area.