San Patricio is a city in San Patricio County in the U.S. state of Texas. The population was 384 at the 2020 census. In the 2000 U.S. Census, a portion of San Patricio was indicated as being in Nueces County. As of the 1990 U.S. Census, the 2010 U.S. Census, and the 2020 U.S. Census, that particular area is indicated as being in San Patricio County.