A post office was established at St. Leon in 1852, and remained in operation until it was discontinued in 1955.

There were 263 housing units at an average density of 37.7 per square mile (14.6/km2).

24.2% of all households were made up of individuals, and 9.9% had someone living alone who was 65 years of age or older.

There were 139 housing units at an average density of 19.4 per square mile (7.5/km2).

15.8% of all households were made up of individuals, and 8.3% had someone living alone who was 65 years of age or older.

St. Leon, Indiana, is served by East Central High School which draws from many surrounding areas as well.