Fulton County is a county in the north-central portion of the U.S. state of Georgia. As of 2018 estimates, the population was 1,050,114, making it the state's most populous county and its only one with over 1 million inhabitants. Its county seat is Atlanta, the state capital. Approximately 90% of the City of Atlanta is located within Fulton County (the other 10% lies within DeKalb County). Fulton County is the principal county of the Atlanta metropolitan area. Fulton County is part of the Atlanta-Sandy Springs-Roswell, GA Metropolitan Statistical Area.