Bowyer began racing at age five in motocross, accumulating over two hundred wins across various disciplines over the next eight years. In 1996 he turned to street stocks at Thunderhill Speedway in Mayetta, Kansas, and by 2001 had claimed Modified championships at Lakeside Speedway in Kansas City and Heartland Park Topeka. In 2002 he joined the NASCAR Weekly Racing Series, posting twelve wins and 32 top-five finishes to finish second in the national standings while also claiming the Midwest champion title.
His breakthrough came at an ARCA race at Nashville Superspeedway in 2003, where he led 47 laps and finished second driving for Scott Traylor. That performance caught the attention of team owner Richard Childress, who called Bowyer directly to offer him a seat at Richard Childress Racing.
Bowyer joined RCR's Busch Series programme in 2004 and ran his first full Busch season in 2005, finishing second in the championship to Martin Truex Jr. by only 68 points. He made his Nextel Cup debut on April 23, 2005, at Phoenix International Raceway before being promoted to the No. 07 Jack Daniel's Chevrolet for the 2006 Cup season, where he finished 21st in points with eleven top-tens and was named NASCAR Rookie of the Year runner-up behind Denny Hamlin.
In 2007 Bowyer delivered one of the season's most memorable images at the Daytona 500, crossing the finish line upside down and on fire after a last-lap crash — an event that encapsulated his fearless racing style. He recovered to score his first Cup win later that year at the Sylvania 300 at New Hampshire Motor Speedway, becoming the fifteenth driver to have won in all three of NASCAR's top national series.
His most statistically successful season at RCR was 2008. Bowyer won his second Cup race at Richmond International Speedway and clinched the NASCAR Nationwide Series championship at Homestead-Miami Speedway, edging Carl Edwards by 21 points. He continued to perform consistently through 2010 and 2011, winning consecutive fall Talladega races, but was narrowly beaten by Jimmie Johnson by 0.002 seconds in a four-wide finish at Talladega in spring 2011 — one of the closest finishes in Cup Series history. At the end of 2011, after eight seasons with RCR, Bowyer signed a three-year deal to join Michael Waltrip Racing.
Bowyer's move to MWR in 2012 yielded his best statistical season. He won three races including his first road-course victory at Sonoma and a Chase race at Charlotte, finished second in the championship by a single point over Jimmie Johnson, and was at the centre of a fiery on-track rivalry with Jeff Gordon that culminated in a pit-road confrontation at Phoenix after Gordon intentionally wrecked Bowyer in the closing laps.
The 2013 season brought controversy when Bowyer's car spun late at Richmond International Raceway in circumstances that NASCAR investigated as a possible attempt to manipulate Chase eligibility for MWR teammate Martin Truex Jr. NASCAR docked all three MWR teams 50 championship points and fined the organisation $300,000. Bowyer retained his Chase spot and had already clinched entry at Bristol.
The subsequent two seasons at MWR were less successful, and the team announced it would not field full-time entries in 2016. Bowyer spent 2016 with HScott Motorsports in a contractually difficult arrangement that ended in litigation; Bowyer and HScott Racing ultimately reached a confidential settlement.
Bowyer joined Stewart–Haas Racing in 2017 to drive the No. 14 Ford, inheriting Tony Stewart's iconic number. His first SHR seasons were streaky, but 2018 brought a resurgence. He ended a 190-race winless drought with a victory at Martinsville in March, then added a second win at Michigan to return to the Cup playoffs for the first time since 2015. He advanced to the Round of 8 before elimination at Phoenix.
In 2019 Bowyer made the playoffs on the strength of a fifth-place finish at Indianapolis despite going winless, finishing ninth in points — his best since 2013. The 2020 season was his last; he qualified for the playoffs with seven top-tens and revealed in October 2020 that he would retire from full-time competition to join Fox Sports full-time.
Beginning with the 2021 season, Bowyer became a permanent fixture in the Fox Sports NASCAR broadcast booth alongside Mike Joy and Kevin Harvick. His candid, enthusiastic on-air personality and firsthand racing knowledge made him a prominent voice in NASCAR media coverage.
Bowyer won ten NASCAR Cup Series races across his 15-year career, scoring most of his wins at tracks historically considered to reward driver aggression — superspeedways, Richmond, Martinsville, and road courses. He was a consistent playoff contender through his prime years, achieving a career-best second in the championship in 2012. The 2008 Nationwide Series title remains his only series championship as a driver. Off track he founded Clint Bowyer Racing, a dirt late model team that won the Lucas Oil Dirt Late Model championship in 2014 with Don O'Neal.