St. Paul is a census-designated place (CDP) in San Patricio County, Texas, United States.

[1] According to the United States Census Bureau, the CDP has a total area of 3.3 square miles (8.5 km2), all land.

There were 209 housing units at an average density of 63.4 per square mile (24.5/km2).

22.3% of all households were made up of individuals, and 14.5% had someone living alone who was 65 years of age or older.

St. Paul is served by the Sinton Independent School District.