Churchill Downs, located on Central Avenue in south Louisville, Kentucky, United States, is a Thoroughbred racetrack most famous for hosting the Kentucky Derby annually. It officially opened in 1875, and held the first Kentucky Derby and the first Kentucky Oaks in the same year. Churchill Downs has also hosted the renowned Breeders' Cup on eight occasions, most recently in 2011. Churchill Downs Incorporated owns and operates the racetrack.

In 2009, the Horseplayers Association of North America introduced a rating system for 65 Thoroughbred racetracks in North America. Churchill Downs was ranked number 5 on this list.

The track is named for John and Henry Churchill, who leased 80 acres (320,000 m²) of land to their nephew, Colonel Meriwether Lewis Clark, Jr. (grandson of explorer William Clark). Clark was president of the Louisville Jockey Club and Driving Park Association, which formed in 1874. His father-in-law, Richard Ten Broeck, was an accomplished horse breeder and trainer, and introduced Clark to horse racing, attending the English Derby at Epsom Downs outside London.