Cumming is a city in Forsyth County, Georgia, United States, and the sole incorporated area in the county. It is part of the Atlanta metropolitan area. Its population was 5,430 at the 2010 census, up from 4,220 at the 2000 census. Surrounding unincorporated areas with a Cumming mailing address have a population of around 100,000. It is the county seat of Forsyth County.