San Patricio, TX has a population of 517 and is the 19,302nd largest city in the United States. The population density is 134 per sq mi which is 40% higher than the Texas average and 48% higher than the national average. The median age in San Patricio is 47 which is approximately 39% higher than the Texas average of 34. In San Patricio, 66% of the population over 15 years of age are married, 70% speak English and 29% speak Spanish. 76% of San Patricio residents were born in Texas, 17% were born out of state, 2% were born outside of the United States and 5% were foreign born.