Stewart grew up in Bixby, Oklahoma and began racing quarter midgets at the age of seven. He transitioned to sprint cars at 16, learning the craft under the guidance of driver Andy Hillenburg. His early development covered a wide range of sprint car disciplines and track types that formed the foundation for his later success on national tours.
Stewart first appeared in the World of Outlaws Sprint Car Series in 1995 and made the commitment to run the full schedule in 2005, earning the series Rookie of the Year title in that debut full season. He returned for the full 2008 campaign with Roth Motorsports.
Alongside his 410 program, Stewart was a formidable competitor in 360ci sprint car racing. He was the 2007 champion of the Northwest Sprint Challenge Speedweek and won the American Sprint Car Series national touring title in 2009 and again in 2011, the second title coming by a single point over Johnny Herrera. He won the Knoxville 360 Nationals five times and claimed the Canadian Sprint Car Nationals on three occasions, tying Steve Poirier for the most wins in that event. The National Sprint Car Hall of Fame and Museum named him 360 Sprint Car Driver of the Year in both 2009 and 2011.
The most prominent stretch of Stewart's career came when he joined the newly formed Larson Marks Racing — later renamed Kyle Larson Racing — for the 2014 season. Over five seasons with the organization he won 35 feature events across multiple series. The highlight was the 2015 Kings Royal at Eldora Speedway, one of the most prestigious events on the sprint car calendar, which he claimed against a star-studded field. That same year he finished second in the World of Outlaws standings behind Donny Schatz, the best championship result of his career. In the 2016 off-season he won the Winter Heat Sprint Car Showdown championship at Cocopah Speedway.
For 2019 Stewart moved to CJB Motorsports, replacing David Gravel. He won the World of Outlaws special event at Nashville's Fairgrounds Speedway but departed the team at season's end, citing a lack of chemistry. After weighing retirement, he returned for 2020 with the No. 71 car owned by Bernie Stuebgen. During that pandemic-shortened season he won the prestigious Summer Nationals at Williams Grove Speedway and a race at Lakeside Speedway while substituting for David Gravel, who was fulfilling NASCAR Gander Outdoors Truck Series commitments with Jason Johnson Racing.
At the conclusion of the 2020 season Stewart announced his retirement from active competition. He channeled his passion for the sport into track promotion, purchasing his home facility Port City Raceway to continue his involvement in sprint car racing from the other side of the pit gate.
Stewart's career encapsulates the dual-discipline sprint car competitor: equally at home in the high-budget 410 World of Outlaws arena and the grassroots 360 national tours. His five Knoxville 360 Nationals titles and back-to-back ASCS championships established him as one of the dominant 360 drivers of the 2000s, while the 2015 Kings Royal victory gave him a marquee result on sprint car racing's biggest stage.