Louisville (usually pronounced /ˈluː.əvəl/ ( listen); see Pronunciation below) is the largest city in the U.S. state of Kentucky, and the county seat of Jefferson County. Since 2003, the city's borders have been coterminous with those of the county because of a city-county merger. The city's population at the 2010 census was 741,096. An important internal shipping port in the 19th century, Louisville is today most well known for the Kentucky Derby, the widely watched first race of the Triple Crown of Thoroughbred Racing.

Louisville is situated on the Ohio River in north-central Kentucky at the Falls of the Ohio. Because it includes counties in Southern Indiana, the Louisville metropolitan area is often referred to as Kentuckiana. The river forms the border between Kentucky and Indiana. A resident of Louisville is referred to as a Louisvillian. Although situated in a Southern state, Louisville is influenced by both Southern and Midwestern culture. It is sometimes referred to as either the northernmost Southern city or the southernmost Northern city in the United States.