San Antonio, or unofficially San Ann as the locals call it, 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. It lies within Florida's 5th congressional district. The population was 1,138 at the 2010 census. It was established as a Catholic colony by Judge Edmund F. Dunne. The city derives its name from Saint Anthony of Padua. Saint Leo University is located nearby.