Marks was born in St. Louis, Missouri. As a boy he went with his grandfather (who lived in Iowa), to see local Midwest racers such as Dick Trickle, Ken Schrader, and the Wallace brothers battle on dirt tracks. His family moved to Menlo Park, California when Marks was eight. Marks attended race school while in high school and in 1998 competed in his first race, in the street stock division at Altamont Raceway Park in Tracy, California. At the same time as his racing career was beginning, he was attending California State University with the intention of obtaining a degree in Sports marketing. Marks withdrew from college 14 credits shy of completing his degree to focus on racing.
At 18, Marks entered the SCCA Regional Racing Series, and later the Speed World Challenge Series. With success in the SCCA, Marks moved to the Rolex Sports Car Series GT Class in 2004 where he met good friend Joey Hand. Switching between the GT class and the World Challenge, Marks raced up four wins, eight podiums, and thirteen top tens between the two series. In 2005 Marks again raced in the Rolex Sports Car Series where he won 3 races with teammate Joey Hand. At the same time, Marks teamed with Bill Auberlen in the Continental Tire Sports Car Challenge for Turner Motorsport, finishing 3rd in points with 5 poles and 5 wins in 9 starts.
In 2006, Marks left road racing to pursue a career in NASCAR. In 2006, Marks raced for RAB Racing in the ARCA RE/MAX Series, driving their No. 65. Although he did not pick up any wins in his two years there, Marks turned many heads with his driving ability. In 2007 he was picked up by Germain Racing of the Craftsman Truck Series to drive their No. 03 truck. Marks again impressed many with an eighth-place finish at Homestead-Miami Speedway. This cemented his Future as the driver of the No. 9 Crocs/Construct Corps Toyota for 2008, running for Rookie of the Year.
In 2008, Marks raced in the Truck Series, the Nationwide Series, and the ARCA RE/MAX Series for a number of teams. He won the pole position for the NASCAR Craftsman Truck Series race at Texas Motor Speedway as well as the ARCA RE/MAX Series season opener at Daytona International Speedway. Marks returned to the Camping World Truck Series for 2011, driving for Turn One Racing in the No. 66 Chevrolet.
On December 17, 2009, Lakeville, Minnesota's Win-Tron Racing announced that Marks would drive their No. 32 Toyota in the 2010 ARCA Racing Series season.
Marks and Michael McDowell operate a karting facility called the GoPro Motorplex, located 30 miles north of Charlotte, North Carolina. The facility opened in October 2012, and was inspired by another karting track located in Parma, Italy.
(key) (Bold – Pole position awarded by qualifying time. Italics – Pole position earned by points standings or practice time. * – Most laps led.)
In the summer of 2015, Marks ran the road course races at Road America and Mid-Ohio in the Xfinity Series, driving the No. 42 Chevrolet for Chip Ganassi Racing, owned by Harry Scott, Jr..
In 2016, Marks expanded his Chip Ganassi Racing schedule in the Xfinity Series, driving the No. 42 in several races starting at Las Vegas Motor Speedway. At the Mid-Ohio Sports Car Course, Marks led a race-high 43 laps in a race plagued by rain to claim his first NASCAR victory; he dedicated the win to former Ganassi driver Bryan Clauson, who had died earlier in the week in an accident. In 2017, Marks returned to the Xfinity Series driving the No. 42 for Chip Ganassi Racing at the Mid-Ohio Sports Car Course finishing 9th and at Road America finishing 4th. On October 15, Marks joined Tommy Baldwin Racing's No. 7 for his return to the Cup Series at Talladega Superspeedway. It was his first non road course start in the Monster Energy series. However he finished last after getting into an incident.
