Willow Springs International Motorsports Park (commonly referred to as Willow Springs) is located in Willow Springs near Rosamond, California, about 80 mi (130 km) north of Los Angeles. It is the oldest permanent road course in the United States. Construction began in 1952, with the inaugural race held on November 23, 1953. The main track is a 2.500 mi (4.023 km) long road course that is unchanged from its original 1953 configuration. The elevation changes and high average speeds make it a favorite of many road racing drivers.

Willow Springs hosted two NASCAR Grand National races in 1956 and 1957 on the original road course (then known simply as Willow Springs Speedway), won by Chuck Stevenson and Marvin Panch, respectively. The track also hosted five NASCAR Winston West Series events, the first two in 1955 and 1956 and the other three between 1984 and 1986. Willow Springs also hosted one NASCAR Southwest Series race in 1986.

There are seven tracks at Willow Springs. The largest and most well known track is Willow Springs International Raceway (commonly referred to as Big Willow). Other racing facilities include The Streets of Willow (1.8-mile road course), The Horse Thief Mile (road course), The Speedway at Willow Springs (1/4-mile paved oval), Willow Springs Kart Track (a .625-mile, nine-turn paved sprint track), The Playpen (a 1/4-mile paved training track), and the Walt James Stadium (Clay Oval and Paved Oval).

Efforts by fans resulted in the State of California declaring Willow Springs International Raceway as a California Point of Historical Interest in 1996.

The original intent was to create a replica of the Indianapolis Motor Speedway oval, but space constraints resulted in its final configuration. Ken Miles was among several people involved in planning the layout. The first event was held on November 23, 1953.

The course was very fast from the outset and quickly earned the nickname "The Fastest Road in the West."

In 1962, the course was sold to Bill Huth, who paid $116,000 for the facility and hoped to use the main straight for drag racing. Huth purchased the lease outright in 1980 and soon began expanding the facility. The initial 230 acres expanded to 600 acres with the purchase of adjacent land. A second track, the Streets of Willow, was constructed next, and a third track, Horse Thief Mile, was added in 2003.

Huth died in 2015 at the age of 91.

In June 2024, the park was listed for sale.

Willow Springs Raceway (commonly called Big Willow or sometimes The Big Track) is a 2.50 mi (4.02 km) paved road course consisting of 9 turns.

• Turn 1: "Castrol corner" is a 90-degree high-speed left-handed turn.
• Turn 2: "The Rabbits Ear" is a double-apex sweeping turn
• Turn 3/4: "The Omega" is an uphill and downhill section with a camber change.
• Turn 5: A quick left-handed turn that sets up for the fastest sections of the track.
• Turn 6: Monroe Ridge
• Turn 7: Repass Pass
• Turn 8: Sometimes called, "The Sweeper," turn 8 is a high-speed right-hand corner. The lead-in to this turn is the fastest section of the racetrack.
• Turn 9: A right-handed turn with a big dip before the apex. This is the final turn before the front straightway to the finish line.

The Streets of Willow Springs (commonly called The Streets of Willow or sometimes Streets) is a 1.80 mi (2.90 km) paved roadcourse. The track was repaved in late 2021 after numerous complaints of the deteriorating quality of the track.

Opened in 2003, the Horse Thief Mile (sometimes called The Mile) is a 1.00 mi (1.61 km) paved roadcourse featuring 11 turns as well as numerous elevation changes. It was designed to simulate a winding mountain road.

Willow Springs has been featured in numerous forms of media including movies, television, music videos and video games.

Willow Springs has been used for filming for motion pictures such as 1:42:08: A Man and His Car, the 1969 Disney film The Love Bug and Ford v Ferrari (Le Mans '66).

Willow Springs has been used for several TV shows including British BBC program Top Gear, several episodes of Wheeler Dealers and Jay Leno's Garage.

The track was featured in the Japanese Best Motoring International "American Touge" video special.

The track is in the 1985 Christopher Cross music video "Every Turn of the World", as well as "It's the Things You Do" by Five.

Willow Springs International Motorsports Park was the venue of a photoshoot session by Playboy for its Playmate pictorial and centerfold featuring Alyssa Arcè as Miss July 2013. The photographs were featured in the magazine's July-August 2013 issue.

Willow Springs tracks have been featured in video games including Need for Speed: ProStreet, Need for Speed: Shift, Gran Turismo 6, Gran Turismo Sport, Gran Turismo 7, Project CARS, and iRacing.

The overall track record is held by Michael Andretti in a 1987 CART Indycar. Andretti completed a lap of the 2.5 mi (4.0 km) main track in 1 minute, 6.050 seconds for an average speed of 136 miles per hour (219 km/h).

As of March 2017, the fastest official race lap records at Willow Springs International Motorsports Park are listed as:

Category	Time	Driver	Vehicle	Event
Permanent Road Course ("Big Willow"): 4.023 km (1953–present)
Can-Am	1:15.900	Al Lamb	Frissbee GR2	1987 Willow Springs Can-Am round
TA	1:20.839	Greg Pickett	Ford Mustang Trans-Am	2017 Willow Springs Trans-Am West Coast round
Group 4	1:37.100	Frank Monise	Lotus 23	1966 SCCA Regional Willow Springs

Option hosted an early exhibition drift event in 1996.

During the early 1980s, the factory-backed Renault Formula One team often used Willow Springs to test their cars before the early season United States Grand Prix West held at Long Beach in Los Angeles.

ChampCar Endurance Series hosts a double-8+7-hour endurance race on Big Willow.

• Buttonwillow Raceway Park
• Chuckwalla Valley Raceway

• Willow Springs International Raceway Official Site
• Willow Springs International Motorsports Park archive at Racing-Reference
• Google Images satellite view of raceway
• Guide to Willow Springs Raceway