Duluth is a city in Gwinnett County, Georgia and an increasingly more affluent and developed suburb of Atlanta. Unincorporated portions of Forsyth County also have Duluth as a mailing address, though this area is outside city limits. Much of the adjacent city of Johns Creek (incorporated in 2006) uses one of the Duluth ZIP codes. As of the 2010 census, the city had a population of 26,600. Duluth is a suburb of Atlanta, close to Interstate 85.