Fulton County is located in the north-central portion of the U.S. state of Georgia. As of the 2020 United States census, the population was 1,066,710, making it the state's most-populous county and its only one with over one million inhabitants. Its county seat and largest city is Atlanta, the state capital. Approximately 90% of the City of Atlanta is within Fulton County; the other 10% lies within DeKalb County. Fulton County is part of the Atlanta-Sandy Springs-Roswell, GA Metropolitan Statistical Area.