DeKalb County is located in the north central portion of Georgia. As of the 2020 census, the population was 764,382, making it Georgia's fourth-most populous county. Its county seat is Decatur.
DeKalb County is included in the Atlanta-Sandy Springs-Roswell, GA Metropolitan Statistical Area. It contains roughly 10% of the city of Atlanta (the other 90% lies in Fulton County). DeKalb is primarily a suburban county.