DeKalb County (// dee-kab) is a county located in the U.S. state ofGeorgia. The population of the county was 691,893 at the 2010 census. Itscounty seat is the city of Decatur. It is bordered to the west by Fulton Countyand contains roughly 10% of the city of Atlanta. (The other 90% lies in Fulton County).
DeKalb County is included in the five-county core of the Atlanta metropolitan statistical area. It is the third-most-populated county in Metro Atlanta and the state, just behind Gwinnett County. Prior to the 2010 Census, DeKalb County historically ranked second behind Fulton County for many years. It is the most diverse county in Georgia. DeKalb is primarily a suburban county, and is the second-most-affluent county with an African-American majority in the United States, behind Prince George's County, Maryland, in suburban Washington D.C. However, unlike in Prince George's County, DeKalb County's communities with a majority African-American population tend to fall below the county's median income, while communities with a majority White population tend to have incomes above the county's median.
In 2009, DeKalb earned the Atlanta Regional Commission's "Green Communities" designation for its efforts in conserving energy, water and fuel; investing in renewable energy; reducing waste; and protecting and restoring natural resources.
In recent years, some communities in North DeKalb have incorporated, following a trend in other suburban areas around Metro Atlanta. Dunwoody & Brookhaven are now the largest cities in the county.