 Its county seat is Fayette.Its name is in honor of the Marquis de Lafayette (or de la Fayette), who aided General George Washington in the American Revolutionary War.Fayette County was established on December 20, 1824, during Lafayette's historic tour of the 24 United States

According to the U.S. Census Bureau, the county has a total area of , of which is land and (0.3%) is water.