The Chicagoland 300 was a NASCAR Xfinity Series stock car race held annually at Chicagoland Speedway in Joliet, Illinois. In 2008 the race has been held at night under Chicagoland Speedway's new lighting system, after being held as a day race for the previous 7 years. However, in 2011, the race returned to daytime. From 2016 to 2017, it served as the final race of NASCAR's "regular season" for the Xfinity Series, Following the race, the top 12 drivers in points standings advance to the seven-race NASCAR Xfinity Series playoffs. Starting in 2018, the race moved to June, the weekend before 4th of July. The new race that Las Vegas Motor Speedway acquired from Kentucky Speedway took Chicagoland's former spot.

Chicagoland Speedway is a 1.520 mi (2.446 km) tri-oval speedway with a curved backstretch in Joliet, Illinois, southwest of Chicago. The speedway opened in 2001 and actively hosted NASCAR racing including the NASCAR Cup Series until 2019. Until 2010, the speedway has also hosted the IndyCar Series, recording numerous close finishes including the closest finish in IndyCar history. The speedway is owned and operated by NASCAR.