Prestonsburg is a city in and the county seat of Floyd County, Kentucky, United States. It lies in the eastern part of the state, along the banks of the Levisa Fork of the Big Sandy River. It was founded in 1797 by Col. John Preston—for whom it was named—along with Solomon Stratton, Matthias Harman and Andrew Hood. The population was 3,612 at the 2000 census.