American open-wheel car racing is the highest form of professional formula racing for open-wheel single-seater cars in North America.^[1] The sport was administered by the American Automobile Association (AAA) in 1905 until 1955 when the United States Auto Club (USAC) ran open-wheel racing starting from 1956 after the AAA dissolved its Contest Board in the wake of the 1955 Le Mans disaster and the fatal accident of driver Bill Vukovich.^[2][3] USAC remained the sole governing body until 1979 when a group of disenchanted race team owners established the Championship Auto Racing Teams (CART) series.^[4] A disagreement between CART and Indianapolis Motor Speedway president Tony George resulted in the establishment of the Indy Racing League (IRL) in 1996 and the series rivalled CART before the latter went bankrupt in 2003 and was renamed the Champ Car World Series (CCWS) in 2004.^[5][6] The CCWS and the IRL merged in February 2008 to unify American open-wheel car racing and the merged body has run the sport under the IndyCar Series name since then.^[7][8]

The season consists of a series of races held variously on permanent road courses, closed city streets and oval tracks, usually in the United States and in a few cases abroad.^[5][9] The Drivers' Championship is presented to the most successful open-wheel driver over the course of the season through a points system based on individual race results.^[5][10] The Drivers' Championship is won when it is no longer mathematically possible for another competitor to overtake their points total regardless of the outcome of the remaining races, although is not officially awarded until the Victory Lap Celebration banquet that takes place after the season has ended.^[11] The winning driver and team owner are presented with a replica of the sterling silver Astor Cup and the driver's name is laser-etched into three black granite bases that support the permanent trophy on display in the Indianapolis Motor Speedway Museum.^[12]

As of 2023^[update], 67 drivers from 11 different countries have won a national American open-wheel championship.^{[lower-alpha 1][15]} The first national American open-wheel champion was Barney Oldfield in the 1905 AAA Championship Car season, and the current national title holder is Álex Palou in the 2023 IndyCar Series. A. J. Foyt holds the record for the most Drivers' Championships, having won the title on seven occasions. Scott Dixon is second with six titles, and Mario Andretti, Sébastien Bourdais, and Dario Franchitti are joint third with four titles each.^[15] Bourdais also holds the record for the most consecutive Drivers' Championships with four CCWS championships won between the 2004 and 2007 seasons,^[16] which is also the record for the most overall CART/CCWS titles.^[17] Louis Meyer and Ted Horn hold the record for the most AAA titles, having won the sanctioning body's championship three times. Foyt was the most successful competitor of the USAC era with seven series titles.^[18] Dixon is the most successful driver in the IndyCar Series with six series championships.^[19]

Drivers in bold are entered in the 2023 IndyCar Series.