South Vacherie is a census-designated place (CDP) in St. James Parish, Louisiana, United States.

[2] According to the United States Census Bureau, the CDP has a total area of 15.5 square miles (40.2 km2), all land.

The "unofficial" divider is Louisiana Highway 3127 which runs through the town from east to west.

Another divider that is commonly accepted for the dividing line of Front Vacherie and Back Vacherie is St Patrick's St which runs east to west approximately 1 1/8 miles south of LA Hwy.

As of the census[7] of 2000, there were 3,543 people, 1,233 households, and 976 families residing in the CDP.

18.3% of all households were made up of individuals, and 8.8% had someone living alone who was 65 years of age or older.