The Brickyard 400, currently known for sponsorship reasons as the Brickyard 400 presented by PPG, is an annual NASCAR Cup Series points race held at the Indianapolis Motor Speedway in Speedway, Indiana, United States. The inaugural race was held in 1994 and was the first race other than the Indianapolis 500 to be held at the Indianapolis Motor Speedway since 1916. In its inaugural running, the Brickyard 400 became NASCAR's most-attended event, drawing an estimated crowd of more than 250,000 spectators. The race also paid one of NASCAR's highest purses. From 1994 to 2020, the race was held on the 2.5-mile oval, for a distance of 400 miles. The race was put on hiatus for three years (2021–2023) in favor of the Verizon 200 at the Brickyard which was run on the combined road course and run a distance of 200-mile (321.869 km). The event returned to the oval in 2024 season.

In most years since 1994, the event has traditionally been held on the last weekend of July or the first weekend of August. In 2018–2019, after schedule realignments, NASCAR moved the race to the weekend after Labor Day, where it served as the last race of the regular season. In 2020 only, it was held on Independence Day weekend. In 2021, the event was moved back to late-July and was held on the Road Course.

The names of the winners of the Brickyard 400 are inscribed on the PPG Trophy, which is permanently housed at the Indianapolis Motor Speedway Museum. Jeff Gordon won the inaugural Brickyard 400 on August 6, 1994. He is the most-successful driver in the history of the race, with a record five victories and three pole positions. Gordon also holds the most laps completed, most laps led, and most earnings in the race. Hendrick Motorsports was the most successful team with 11 total wins and 5 poles. Bubba Wallace is the defending race winner, having won it in 2025.

The Indianapolis Motor Speedway opened in 1909, and the first Indianapolis 500 was held in 1911. After initially hosting multiple race meets in 1909–1910, it became a tradition that the Indianapolis 500 would be the only race held at the track annually. With the exception of a race meet the weekend after Labor Day in 1916, no other races were held at the track through 1993. As the NASCAR Winston Cup Series began to grow in stature and popularity, speculation began to grow in the 1980s and early 1990s about the possibility of holding a race at Indy. From 1971 to 1980, NASCAR held races at Ontario Motor Speedway, which was built as a replica of Indianapolis. With their experiences at Ontario, it was generally presumed that the stock cars would find Indy's nearly identical layout equally competitive. In the mid-to-late 1960s, stock car racing slowly began to develop a following in Indiana, with the introduction of the USAC Stock Car Yankee 300 at Indianapolis Raceway Park and the State Fair Century at the Fairgrounds. Later, the Kroger 200 at the IRP oval became a popular stop on the NASCAR Busch Series.

During the reigns of Tony Hulman (1946–1977) and subsequent Speedway presidents John Cooper (1980–1982), and Joe Cloutier (1978–1979, 1983–1989), the idea of hosting a second race at the Speedway was considered from time to time, but never seriously pursued by the board of directors. Cooper had talks with NASCAR, but Cloutier in particular, seemed the most resistant. Not only was tradition and fan interest an issue, but logistical scheduling issues were also obstacles. The congested and aging Gasoline Alley garage area, narrow pit lane, existing retaining walls and catch fences were considered insufficient for the large, heavy stock cars, thus significant capital improvements would be required to properly host NASCAR. Cloutier wanted to assure that a second race at the Speedway would outdraw Indianapolis 500 time trials, otherwise it would not make financial sense.

Around 1969, USAC proposed a race at the Indianapolis Motor Speedway for the USAC Stock Car division. It was to be called the "Tony Hulman Classic", but Hulman and the Speedway management declined the offer. The race would have had to have been held in the autumn, since all desirable summer dates were already taken. For instance, the July 4 weekend was already taken by the Firecracker 400, which would have prevented any NASCAR stars from crossing over to participate; plus several USAC regulars were known to pick up rides for Daytona. Labor Day weekend was already crowded with the USAC California 500 at Ontario, the NASCAR Southern 500 at Darlington, and the NHRA U.S. Nationals at nearby IRP. No progress towards scheduling a stock car race, whether USAC or NASCAR, was ever taken before Tony Hulman died in 1977.

In 1980, due to a tax dispute with the City of Daytona Beach and Volusia County, Bill France openly threatened to move the NASCAR Firecracker 400 to the Indianapolis Motor Speedway. A few weeks later, however, the parties reconciled, and the plan to move the race was withdrawn.

In the summer of 1979, during the first USAC/CART Split, a proposal was made to hold a second race at the Indianapolis Motor Speedway. After the California 500 switched alliances mid-season to become a CART series race, USAC proposed a Labor Day weekend race meet that would consist of a USAC Stock Car/Championship Car doubleheader. A 250-mile stock car race on Saturday would be followed by a 250-mile Indycar race on Sunday. However, the plan never materialized. One of the issues noted was a potential conflict with the NHRA U.S. Nationals at nearby IRP. Even still, rumors of a late-summer stock car race persisted for another year or so. Speculation grew after Ontario Motor Speedway closed and opened up a date on the NASCAR schedule. In early 1982, then-Speedway president John Cooper was said to have made a 'hand-shake' deal with Bill France for a race, but it was vetoed by Mary F. Hulman. Cooper subsequently resigned, saying the details had never really been ironed out, and talks about a stock car race at Indy cooled for the next several years.