Radcliff is a home rule-class city in Hardin County, Kentucky, in the United States. The population was 21,692 at the 2010 census, and in 2016 the estimated population was 22,490. It is included in the Elizabethtown–Fort Knox Metropolitan Area.Its economy is largely dominated by the adjacent U.S. Army base Fort Knox and by the nearby city of Elizabethtown. Radcliff's population previously fluctuated greatly depending on the deployments of the units at the base, but the BRAC reorganization of 2005, and the quartering of the U.S. Army's Human Resources Command to Fort Knox has created a larger and more stable population.