Fort Benning South is a census-designated place and the "build up" portion of Fort Benning military base, in Chattahoochee County, Georgia, United States. It is part of the Columbus, Georgia-Alabama Metropolitan Statistical Area. The population was 11,737 at the 2000 census. As of the census of 2000, there were 11,737 people, 1,852 households, and 1,816 families residing in the CDP. The population density was 528.2/km˛ (1,368.0/mi˛). There were 2,028 housing units at an average density of 91.3/km˛ (236.4/mi˛). The racial makeup of the CDP was 56.82% White, 29.17% African American, 0.90% Native American, 2.08% Asian, 0.46% Pacific Islander, 6.17% from other races, and 4.40% from two or more races. Hispanic or Latino of any race were 12.45% of the population.

There were 1,852 households out of which 81.5% had children under the age of 18 living with them, 90.3% were married couples living together, 5.8% had a female householder with no husband present, and 1.9% were non-families. 1.7% of all households were made up of individuals and none had someone living alone who was 65 years of age or older. The average household size was 3.85 and the average family size was 3.88.