Louisville Muhammad Ali International Airport, formerly known as simply Louisville International Airport, is a civil-military airport in Louisville in Jefferson County, Kentucky. The airport covers 1,500 acres (6.1 km2) and has three runways. Its IATA airport code, SDF, is based on the airport's former name, Standiford Field. Despite being called an international airport, it has no regularly-scheduled international passenger flights, but is a port of entry, handling many UPS Airlines international cargo flights through the United Parcel Service's worldwide air hub, often referred to as UPS Worldport.

Louisville is the most populous city in the Commonwealth of Kentucky, sixth-most populous city in the Southeast, and the 27th-most-populous city in the United States. By land area, it is the country's 24th-largest city, although by population density, it is the 265th most dense city. Louisville is the historical county seat and, since 2003, the nominal seat of Jefferson County, on the Indiana border.