Sinton is a city in San Patricio County, Texas, United States. The population was 5,676 at the 2000 census. It is the county seat of San Patricio County. It is named in honor of David Sinton. According to the United States Census Bureau, the city has a total area of 2.2square miles (5.7Square kilometers), all of it land. As of the census of 2000, there were 5,676 people, 1,845households, and 1,409families residing in the city. The population density was 2,582.0 people per square mile (996.1Square kilometers). There were 2,026 housing units at an average density of 921.6 per square mile (355.6Square kilometers).