San Antonio is a city in Pasco County, Florida, United States. It is a suburban city included in the Tampa-St. Petersburg-Clearwater, Florida Metropolitan Statistical Area. The population was 655 at the 2000 census, although local officials claim the true population in 2000 was 842. As of 2004, the population recorded by the U.S. Census Bureau is 913. It was established as a Catholic colony by Judge Edmund F. Dunne, and Saint Leo University is located nearby.