Grayson County is a county located in the U.S. state of Kentucky. As of the 2020 census, the population was 26,420. Its county seat is Leitchfield. The county was formed in 1810 and named for William Grayson, a Revolutionary War colonel and a prominent Virginia political figure. Grayson County was formerly a prohibition or dry county, but Leitchfield allowed limited alcohol sales in restaurants in 2010 and voted "wet" in 2016.