IndyCar, LLC (stylized as INDYCAR), is an auto racing sanctioning body for American open-wheel car racing headquartered in Indianapolis, Indiana. The organization sanctions two racing series: the premier IndyCar Series with the Indianapolis 500 as its centerpiece, and the developmental series Indy NXT. IndyCar is recognized as a member organization of the FIA through the Automobile Competition Committee for the United States.

The sanctioning body was formed in 1994 under the name Indy Racing League by Hulman & Company, which also owned the Indianapolis Motor Speedway complex, and began competition in 1996. The trademark name INDYCAR was officially adopted on January 1, 2011. The sport of open-wheel car racing, also historically referred to as championship car racing or Indy car racing, traces its roots to as early as 1905. It is the fourth major sanctioning body to govern the sport of Indy car racing, following the American Automobile Association's Contest Board, the United States Auto Club (USAC), and Championship Auto Racing Teams (CART), and operated alongside the Champ Car World Series before acquiring the latter.

Today, IndyCar is owned by the Penske Entertainment Corp., a subsidiary of Penske Corporation. Penske purchased IndyCar and the Indianapolis Motor Speedway from Hulman & Co. in November 2019. In July 2025, Fox Corporation purchased a one-third stake in Penske Entertainment Corp for around $125–135 million.

The term "Indy car" began as a nickname for the cars that competed in USAC's Championship Division of open-wheel racing in the United States, deriving from the sport's most popular competition, the Indianapolis 500. The division's link with Indianapolis soon resulted in the term surpassing the official term "championship car" (or its short form "champ car") in common use and promotions.

The term continued to be used by USAC's replacement as the dominant governing body for open-wheel racing, CART, which called its main series the "CART PPG Indy Car World Series" despite the body not sanctioning the 500. In 1992, during an attempt by CART to broaden their board membership, the Indianapolis Motor Speedway registered the camel case trademark IndyCar with the United States Patent and Trademark Office and licensed it to CART as their new trade name.

In 1996, Indianapolis Motor Speedway President Tony George launched a new national championship racing series, the Indy Racing League. This resulted in a legal battle over the IndyCar trademark: In March 1996, CART filed a lawsuit against the Indianapolis Motor Speedway in an effort to protect their license to the IndyCar mark after the Indianapolis Motor Speedway had attempted to terminate it. In April, the Indianapolis Motor Speedway filed a separate lawsuit against CART to prevent them from further use of the mark.

Eventually a settlement was reached in which CART agreed to give up the use of the IndyCar mark following the 1996 season and the IRL agreed not to use the name before the end of the 2002 season. CART returned to branding as simply CART for 1997, and resurrected the term "champ car" to describe their vehicles.

Following a six-year hiatus, the Indy Racing League announced it would rename their premier series the IndyCar Series for the 2003 racing season. CART, beset by team departures and other financial issues, filed for bankruptcy that year; a trio of former CART team owners were selected by the bankruptcy court to purchase CART's assets, which they used to reorganize as the Champ Car World Series. The two series were unified for the 2008 season, with the unified series using the IndyCar Series name.