LaGrange is a city in and the county seat of Troup County, Georgia, United States. The population of the city was estimated to be 30,858 in 202…LaGrange is a city in and the county seat of Troup County, Georgia, United States. The population of the city was estimated to be 30,858 in 2020 by the U.S. Census Bureau. It is the principal city of the LaGrange, Georgia Micropolitan Statistical Area, which is included in the Atlanta-Sandy Springs-Gainesville, Georgia-Alabama combined statistical area. It is about 60 miles southwest of Atlanta and located in the foothills of the Georgia Piedmont.