McDonough is a city in Henry County, Georgia, United States. The population was 8,493 at the 2000 census. Census estimates of 2008 indicate a population of 19,768, due to growth of the city and extension of the city limits. Inclusion of the unincorporated neighborhoods surrounding McDonough, which are not part of a town/city, raises the population to approximately 30,000. The city is the county seat of Henry County. It is the home of AM radio station Classic Country 1410 WKKP and SCB-TV cable Channel 15 television station.According to the United States Census Bureau, the city has a total area of 7.8 square miles (20.2 km²), of which, 7.8 square miles (20.1 km²) of it is land and 0.04 square miles (0.1 km²) of it (0.51%) is water.The census-designated place of Blacksville and the unincorporated communities of Flippen, Kelleytown, and Ola are located near McDonough, and addresses in those communities have McDonough postal addresses.