Elizabethtown is a home rule-class city and the county seat of Hardin County, Kentucky, United States. The population was 28,531 at the 2…Elizabethtown is a home rule-class city and the county seat of Hardin County, Kentucky, United States. The population was 28,531 at the 2010 census, and was estimated at 31,394 by the U.S. Census Bureau in 2020, making it the 11th-largest city in the state. It is included in the Elizabethtown–Fort Knox, Kentucky Metropolitan Statistical Area, which is included in the Louisville/Jefferson County–Elizabethtown–Madison, Kentucky-Indiana Combined Statistical Area. The Elizabethtown Metropolitan area had a 2019 estimated population of 153,057, making it the 5th-largest metropolitan area in the state.