The Milwaukee IndyFest is an IndyCar Series race held at the Milwaukee Mile in West Allis, Wisconsin. It is the only IndyCar race to be sanctioned by all four of the sport's various governing bodies: AAA, USAC, Championship Auto Racing Teams (and its successor CCWS), and Indy Racing League, LLC.
American Championship car racing debuted at the track in 1937. AAA sanctioned races from 1937–1939, 1941, 1946–1955. USAC sanctioned Championship car races from 1956–1979. In 1980, the race switched to a CART champ car race, and continued through 2003. For most years starting in 1949, Milwaukee hosted the first race following the Indianapolis 500. From 1947–1982, Milwaukee generally hosted two races, one in June, and the other in August or September. Starting in 1983, the second race was dropped. The track was paved in 1954.
In the 1963 Tony Bettenhausen 200, Jim Clark and Team Lotus became the first to win an American Championship race with a rear-engined, monocoque car. After finishing second in that year's Indianapolis 500, Lotus decided to run the car again at Milwaukee and Trenton. Clark and teammate Dan Gurney broke the track record by over a second in qualifying, and Clark led all 200 laps to win, lapping the entire field except for second place A. J. Foyt.
In 1986, the race was scheduled for Sunday June 1. However, due to rain on May 25–26, the Indianapolis 500 was rescheduled to Saturday May 31. After discussions with track, television, and series leaders, the Milwaukee race was pushed back one week to make the accommodation.
In 2004–2006, the track hosted two separate open wheel races: a Champ Car race, and an Indy Racing League event. Starting in 2007, IndyCar became the lone event, and was moved back to the traditional date, the weekend after the Indy 500, through 2009. The race was put on hiatus for 2010, stemming from management difficulties regarding payment of sanctioning fees. In 2011, the race has returned to the IndyCar calendar.