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 in 2000. Surrounding unincorporated areas with a Cumming mailing address have a population of approximately 100,000. Cumming is the county seat of Forsyth County.