Louisville is the largest cityin the U.S. Commonwealth 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 estimated population as of 2009 was 721,594 (consolidated; balance total is 566,503), with a population of 1,266,454 in the Louisville metropolitan area. An important internal shipping port in the 19th century, Louisville is today most well known for the Kentucky Derby, the widely watched first raceof the Triple Crown of Thoroughbred Racing.

Louisville is situated on the Ohio Riverin 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.

The settlementthat became the city of Louisville was founded in 1778 by George Rogers Clark and is named after King Louis XVI of France.