South Wilmington is a village in Grundy County, Illinois, United States. The population was 681 at the 2010 census.Although the name might indicate proximity to the city of Wilmington, South Wilmington is approximately 11 miles southwest of Wilmington, and is separated from it by several communities, including Gardner, Braceville, Godley, and Braidwood.South Wilmington is located at 41°10′24″N 88°16′35″W / 41.17333°N 88.27639°W / 41.17333; -88.27639.According to the 2010 census, South Wilmington has a total area of 0.56 square miles, all land.As of the census of 2000, there were 621 people, 260 households, and 165 families residing in the village. The population density was 1,089.8 people per square mile. There were 287 housing units at an average density of 503.7 per square mile. The racial makeup of the village was 98.39% White, 0.97% from other races, and 0.64% from two or more races. Hispanic or Latino of any race were 2.42% of the population.