The Indianapolis Motor Speedway is an automobile racing circuit located in Speedway, Indiana (an enclave suburb of Indianapolis) in the United States. It is the home of the Indianapolis 500 and the Verizon 200, and formerly the home of the United States Grand Prix. It is the largest sports venue in the world. It is located on the corner of 16th Street and Georgetown Road, approximately six miles (9.7 km) west of Downtown Indianapolis.

Constructed in 1909, it is the second purpose-built, banked oval racing circuit after Brooklands and the first to be called a 'speedway'. It is the third-oldest permanent automobile race track in the world, behind Brooklands and the Milwaukee Mile. With a permanent seating capacity of 257,325, it is the highest-capacity sports venue in the world.Considered relatively flat by American standards, the track is a 2.5-mile-long (4.0 km) rectangular oval with dimensions that have remained essentially unchanged since its construction. It has two 5⁄8-mile-long (1,000 m) straightaways, four geometrically identical 1⁄4-mile (400 m) turns, connected by two 1⁄8-mile (200 m) short straightaways, termed "short chutes", between turns 1 and 2, and between turns 3 and 4.

A modern, FIA Grade One infield road course was completed in 2000, incorporating part of the oval, including the main stretch and the southeast turn, measuring 2.605 mi (4.192 km). In 2008, and again in 2014, the road course layout was modified to accommodate motorcycle racing, as well as to improve competition. Altogether, the current grounds have expanded from an original 320 acres (1.3 km2) on which the speedway was first built to cover an area of over 559 acres (2.3 km2). Placed on the National Register of Historic Places in 1975 and designated a National Historic Landmark in 1987, it is the only such site to be affiliated with automotive racing history.

In addition to the Indianapolis 500, the speedway also hosts NASCAR's Verizon 200 and Pennzoil 150. From 2000 to 2007, the speedway hosted the Formula One United States Grand Prix, and from 2008 to 2015 the Moto GP.

On the grounds of the speedway is the Indianapolis Motor Speedway Museum, which opened in 1956, and houses the Hall of Fame. The museum moved into its current building located in the infield in 1976. Also on the grounds is the Brickyard Crossing Golf Resort, which originally opened as the Speedway Golf Course in 1929. The golf course has 14 holes outside the track, along the backstretch, and four holes in the infield. The site is among the most visited attractions in Indianapolis, with 1 million guests annually. The speedway has served as the venue for the opening ceremonies for the 1987 Pan American Games. The track is nicknamed "The Brickyard" (see below), and the garage area is known as Gasoline Alley.

On November 4, 2019, Hulman & Company announced the sale of its company, including the Indianapolis Motor Speedway, the IndyCar Series and associated enterprises to Penske Corporation, owned by Roger Penske.