Kentucky Speedway is an inactive 1.500-mile (2.414 km) tri-oval intermediate speedway in Sparta, Kentucky. It has hosted various major races throughout its existence, including NASCAR and IndyCar races. The track is owned by Speedway Motorsports, LLC (SMI) and is currently used for weekend track rental. The speedway had a grandstand capacity of 66,000 as of 2020.

In the 1990s, then-Turfway Park owner Jerry Carroll sought new profitable ventures after Turfway Park's decline, deciding to build a modern auto racing facility. Construction started in July 1998 and opened nearly two years later, with an ultimate goal of securing a NASCAR Cup Series race weekend in the near future. However, under Carroll's tenure, a Cup Series date was not given. After a change in ownership to Bruton Smith in 2008, the track gained a Cup Series date in 2011. However, after an inaugural Cup Series weekend plagued by traffic issues and lackluster revenue throughout the following decade, the facility was dropped from the NASCAR schedule starting in 2021 and has since been turned into a multi-use rental complex.

The speedway in its current form is measured at 1.5 miles (2.4 km), with 17 degrees of banking in the first two turns, 14 degrees in the last two turns, 10 degrees on the track's frontstretch, and four degrees on the track's backstretch. Varying sanctioning bodies have disputed the length of the track; NASCAR's official measurement is at 1.5 miles, while IndyCar used a length of 1.48 miles (2.38 km).

Kentucky Speedway is located at an intersection between Interstate 71 and Kentucky Route 35. As of 2019, the facility has a grandstand capacity of 66,000 according to the Lexington Herald-Leader, down from its peak of 106,000 in the 2010s. In total, the facility covers approximately 1,000 acres (400 ha) of land.

In April 1997, Turfway Park owner Jerry Carroll faced declining attendance and betting at the horse racing facility. Seeking new ventures, he visited the newly built Texas Motor Speedway and began exploring the feasibility of building a NASCAR-style superspeedway in Northern Kentucky. According to The Cincinnati Enquirer, the study was expected to last 3–4 months. On January 8, 1998, Carroll announced plans to build a $132 million, 1.5 mi (2.4 km) track with 60,000 seats on 1,000 acres in Gallatin County, Kentucky. Backed by four business partners, he aimed to open the track in fall 1999, begin hosting events in 2000, and eventually expand to 180,000 seats. The project came amid a boom in stock car racing, with several new tracks hoping to secure a NASCAR Cup Series weekend. Carroll expressed hopes of landing a Cup Series date by 2003, starting by relocating a NASCAR Truck Series race from Louisville Motor Speedway, which he had acquired.

By February 1998, Carroll announced an optimistic groundbreaking date of August 1. He expressed interest in hosting Indy Racing League (IRL), Championship Auto Racing Teams (CART), and NASCAR Busch Series events. However, IRL president Tony George stated the league had no plans to race there. Carroll, in contrast, praised NASCAR and its president Bill France Jr. as "very loyal" and moved the groundbreaking date up to July 1. A final date of July 18 was set, with ceremonial events held at Turfway Park for public convenience. Construction began August 1. By then, the project budget had grown to $152 million, and the facility was officially named Kentucky Speedway. Within the first month, about 1,500 personal seat licenses were sold. By year's end, demand for luxury suites prompted an increase from the planned 23 to at least 50. On the advice of track consultant Darrell Waltrip, the banking was adjusted to 14 degrees in the turns and 12 degrees on the straightaways. In February 1999, the track was annexed into Sparta, Kentucky. That same month, Carroll sold his stake in Turfway Park, citing frustration with its decline and a desire to focus on the Speedway. Soon after, Cintas, Ford Motor Company, and Budweiser signed on as corporate sponsors.

In June, Kentucky Speedway announced its first scheduled event: an Automobile Racing Club of America (ARCA) race planned for June 2000. By July, an IRL race was considered "highly probable," and by September, a 300 mi (480 km) event was confirmed for August 2000. In October, ARCA driver Bill Baird completed the first test laps, calling the track "as smooth as a baby's bottom." On November 4, a NASCAR Truck Series race was announced for June 17, 2000, and initial seating was increased to 70,000. A NASCAR Slim Jim All Pro Series race was added for the day before the Truck event. IndyCar driver Greg Ray also conducted test runs that month, and Mark Cassis was named general manager. By early 2000, 70% of the facility was complete. In February, NASCAR indicated the track was not likely to land a Cup Series race but was Busch Series–ready. After complaints during a Truck Series test in May, the surface was repaved by month's end. For its inaugural race weekend, the facility boasted seating for 65,989, 23,000 parking spaces, 104 infield garage spots, and two Outback Steakhouse restaurants—earning praise from drivers and officials alike.

Kentucky Speedway opened on June 16, 2000, with Billy Bigley winning the facility's first event in front of 36,210 fans. The next day's Truck Series race, delayed by heavy rain, drew a near sell-out crowd, with Greg Biffle taking the win. Due to the rain, muddy parking lots forced some spectators to be turned away, causing a 14 miles (23 km) traffic jam on I-71. In response, the track added 50,000 tons of gravel and created a 10,000-car emergency lot. In August 2000, Kentucky was awarded an annual NASCAR Busch Series race, with Kevin Harvick winning the inaugural event on June 16, 2001. The next year, actor and IndyCar hopeful Jason Priestley suffered serious injuries in a 180 mph (290 km/h) crash during a test session. Speedway officials applied for a Cup Series date beginning in 2002, but NASCAR declined, saying it did not align with their expansion plans. Despite expectations, no Cup races were scheduled for 2003 or 2004.