Malcolm Stewart, just like his older brother
James Stewart Jr., began racing at a very young age, competing in amateur motocross events. Although his early career was less decorated than his brother's, he showed consistent improvement and developed into a highly competitive rider. Malcolm Stewart made his professional debut on February 12, 2011, at
Reliant Stadium in
Houston, Texas. For the 2011 season, he rode for team ARMA-Suzuki City-Nitro Circus in the 250cc Lites eastern division. His early career was marked by steady progress in both motocross and supercross events. Over the next several seasons, Stewart raced for various teams, gradually establishing himself as a fair contender in the 250cc division. He would sign with GEICO Honda to contest the 2014 and 2015 supercross seasons; for 2014, he raced the 450cc class, competing well with top 10s in 9 of the first 11 rounds, but missing the last five due to complications of dehydration leading to kidney problems. In 2016, Stewart achieved his first major milestone by winning the AMA 250cc East Supercross Championship with two race wins and six podium finishes. His consistent performances throughout the season, including multiple podium finishes, allowed him to claim the title. This championship marked the highlight of his career in the 250cc class. Stewart sat out the 2016 Lucas Oil Pro Motocross Championship event in order to prepare for the 2017 racing season. Stewart initially struggled to find a full-time ride but participated in select events as a privateer. In 2018 he was signed as a fill-in rider for Joe Gibbs Racing Suzuki. Over time, he gained opportunities with factory-supported teams, including Smartop/MotoConcepts Honda and later
Rockstar Energy Husqvarna Factory Racing. In 2022, Stewart joined the Rockstar Energy Husqvarna Factory Racing team for the full AMA Supercross 450cc season. Following this signing, he began to train with
Aldon Baker. He began finishing consistently in the top five and earned three podium finishes. In 2025 at round 5 in Tampa, Stewart earned his first win of his 450cc class career, over 10 years after joining the premier class. == AMA Supercross/Motocross Results ==