Hardinsburg is a city in Breckinridge County, Kentucky, United States. The population was 2,345 at the 2000 census. It is the county seat of Breckinridge County. By Kentucky state law, it is classified as a fifth class city. The city's namesake, Captain William Hardin, established the city as a frontier fort in 1780.
Hardinsburg is located at 37°46′35″N 86°27′18″W / 37.77639°N 86.455°W / 37.77639; -86.455 (37.776336, -86.455010).
According to the United States Census Bureau, the city has a total area of 3.6 square miles (9.4 km²), of which, 3.6 square miles (9.2 km²) of it is land and 0.1 square miles (0.2 km²) of it (1.65%) is water.