Todd's grandfather, Butch Gilliland, was the 1997 Winston West (now K&N Pro Series West) Champion and made several NASCAR Cup Series and NASCAR Truck Series starts over his career.
Todd's father, David Gilliland, began his NASCAR touring career in 2003 winning five races making a name for himself along the west coast short tracks.
In 2006 David scored his first career Busch Series win at Kentucky. Gilliland drove the No. 84 machine to victory, becoming the first driver of 2006 to win a Busch race who was not also running a full-time Nextel Cup schedule. Announcer Hermie Sadler called the victory "the biggest upset in Busch Series history".
David would go on to compete in the NASCAR Cup Series for 12 years, capturing the pole of the 2007 Daytona 500 for Robert Yates Racing.
Todd started racing at a young age in quarter midgets. He won several Championships including the North Carolina Quarter Midget Association and USAC World Formula National Quarter Midget Championship.
In 2015, Todd made his ARCA debut at Toledo Speedway two days after his 15th birthday. He went on to win, becoming the youngest winner in series history; a record that he still holds today.
In 2016 Todd competed in his first full-time NASCAR K&N West Series season for Bill McAnally Racing. Todd went on to win six total races, including four-in-a-row and securing his first K&N West Series championship.
Todd went on to defend his West Series title in 2017, once again driving for Bill McAnally Racing. Todd won another six races while winning his second championship for the team.
In 2018 Kyle Busch Motorsports announced Todd would compete 19 NASCAR Camping World Truck Series races. Todd won his first pole at Martinsville Speedway in October.