South Vienna is a village in Clark County, Ohio, United States.

Located about halfway between Dayton, OH and Columbus, the South Vienna Corn Festival is held in the area on the weekend after Labor Day.

The village also has the distinction of having Permit #1, issued by the State of Ohio for traffic lights.

[5] According to the United States Census Bureau, the village has a total area of 0.52 square miles (1.35 km2), all of it land.

There were 166 housing units at an average density of 319.2 per square mile (123.2/km2).

25.0% of all households were made up of individuals, and 8.8% had someone living alone who was 65 years of age or older.

16.9% of all households were made up of individuals, and 5.4% had someone living alone who was 65 years of age or older.