American Championship car racing

American Championship car racing, also known as Indy Car racing, is a category of professional-level automobile racing in the United States and North America. As of 2015, the top-level American open wheel racing championship is sanctioned by IndyCar.

Competitive events for professional-level, single-seat open-wheel race cars have been conducted under the auspices of several different sanctioning bodies since 1902. A season-long, points-based, National Championship of drivers has been officially recognized in 1905, 1916, and since 1920. The Indianapolis 500, which itself debuted in 1911, is the marquee event of Indy Car racing.

The open-wheeled, winged, single-seater cars have generally been similar to those in Formula One, though there are important differences. The fame of the Indianapolis 500 leads many to refer to the cars that would typically compete in American Championship car racing as "Indy cars." These machines were popularized during the rising popularity of the CART PPG Indy Car World Series racing in the 1980s and early 1990s.