Growing up in a naval family, Foust spent several years as a child in Scotland, where he discovered rallying and learned to drive on the country roads near his home. He returned to the United States and worked as a golf caddy and school bus driver, of which he was fired, and went into a pre-med track at the University of Colorado, earning a biology degree. He spent his summers at the track, trading seat time in racecars for mechanic work and driver coaching jobs. After college, he began working as an ice driving coach, an instructor at automotive marketing events and competing in anything he could, including rally and drifting. He made the transition to professional racing in 2003, and soon moved to California to begin stunt driving for Hollywood films. With his passion for cars, he has rapidly become one of the busiest professional drivers in the United States. He considers himself fortunate that, in just over ten years of professional racing, he has had the opportunity to compete against the likes of Rod Millen, Colin McRae, Michael Schumacher, Jenson Button and Sebastian Vettel.

Foust has been a stunt driver for films such as The Fast and the Furious Tokyo Drift, Ford vs Ferrari, Need For Speed (film) and The Dukes of Hazzard and set multiple world records with Hot Wheels and Top Gear. He was a prominent competitor in the Formula Drift series, winning the 2007 and 2008 championship. Foust is the first driver in Formula Drift history to win back-to-back series championships. He is the most decorated driver in X Games history with 9 medals. Foust first competed in X Games XIII in 2007 where he won the gold in the rally racing event. He also participated in Rally America in 2009. In 2010 at X Games XVI he won gold in Rally Car Racing and Rally Car Super Rally, driving the Rockstar Energy Ford Fiesta. He also competed in the European Rallycross Championship, becoming the first American to do so. After leaving the drifting scene in favor of RallyCross in 2011, Foust became a regular ERC competitor, taking part in 9 of the 10 rounds of the FIA recognized series finished second overall as well as Global RallyCross – winning the championship. In 2012, Foust continued his success with another Global RallyCross championship.

He was slated to become co-host for the original American version of the motoring television series, Top Gear, on NBC and filmed a pilot before the series was dropped. The series has since been picked up by the History Channel and Foust was the only pilot presenter to be picked up when the program finally made it on air in the U.S. in late 2010. He has also hosted other shows including SPEED Channel’s SuperCars Exposed, SPEED Channel’s Redline TV and ESPN’s Import Tuners. On November 21, 2010, he made his debut for the History Channel series, Top Gear, the American version of the BBC hit series of the same name.

For 2013, Foust medaled in both racing events at X Games XIX Los Angeles with a gold in Gymkhana Grid and silver in RallyCross. These marked his eighth and ninth X Games medals.

At the Chicago Auto Show in February 2014, Foust announced a new partnership with Volkswagen and Andretti Autosport. He drove a Volkswagen New Beetle for the 2014 Global RallyCross Championship season as well as selected events with Marklund Motorsport in the inaugural season of the FIA World Rallycross Championship. He became the first, and so far only, driver from outside Europe to win a round of the championship, winning the 2014 World RX of Finland. As the US rallycross series has changed names from Global Rallycross to America’s Rallycross and Nitro Rallycross, Foust has finished runner up in the championship 3 times and won the NRX championship in 2019. He holds the longest running streak of Heat victories in rallycross worldwide at 25 and is currently the winningest driver in the US.

In Summer 2015 he started shooting the sixth and final season of Top Gear completing 72 episodes.