Dillon grew up in the Piedmont Triad of North Carolina in a family deeply embedded in NASCAR. His father Mike Dillon is a retired NASCAR driver and RCR executive. Ty began racing in go-karts and Bandoleros before moving through the K&N Pro Series East, where he scored a win in August 2010 at Gresham Motorsports Park. He made three ARCA starts in 2010, winning twice, and then ran his first full ARCA season in 2011, winning seven races to claim the series title by a 340-point margin over Chris Buescher.
Dillon debuted in the Camping World Truck Series in 2011 and ran the full schedule for RCR in 2012, recording five top-ten finishes in the first five races of that season. He scored his first Truck Series win at Atlanta Motor Speedway on August 31, 2012. In 2013, Dillon finished second in the Truck Series championship standings behind Matt Crafton, was named the series' Most Popular Driver, and won the 100th race for a No. 3 vehicle in NASCAR at Texas. A late-race collision with a teenage Chase Elliott at the Canadian race became one of the more talked-about moments of his Truck tenure.
Dillon made his Nationwide Series debut in mid-2012 and moved full-time to the series in 2014, driving the No. 3 Chevrolet for RCR — the same number his brother Austin had driven before moving to the Cup Series. He won his first career Xfinity Series pole at Las Vegas and secured additional poles at Kentucky and Kansas that year. His best season-long performance came in 2015, when he finished third in the championship standings, recording 25 top-tens and twelve top-fives despite not winning a race. In 2016, Dillon advanced into the Xfinity Chase but was eliminated before the championship round; he won the Dash 4 Cash bonus at Richmond and finished fifth in the championship.
Dillon made his Cup debut in 2014 and ran part-time through 2016 before landing a full-time ride with Germain Racing for the 2017 season, driving the No. 13 GEICO Chevrolet through 2020. His Cup career was largely defined by consistency at superspeedways — he scored multiple top-ten finishes at Daytona and Talladega — while struggling to compete at intermediate tracks with the small-budget team. His best career Cup finish of third came at the 2020 YellaWood 500 at Talladega, promoted from fourth when Matt DiBenedetto was penalized. Germain Racing shut down after 2020 due to the loss of its GEICO sponsorship.
After Germain closed, Dillon spent 2021 through 2024 piecing together starts across teams including Gaunt Brothers Racing, Petty GMS Motorsports (driving the No. 42 in 2022), and Spire Motorsports (No. 77 in 2023, where he finished last among full-time Cup drivers). He returned to full-time Cup competition in 2025 with Kaulig Racing, driving the No. 10 Chevrolet.
Dillon represents the second generation of Childress family talent in NASCAR, following in the wheel tracks of brother Austin and grandfather Richard. Though his Cup record remained winless, his success in the Truck and Xfinity series — particularly the 2011 ARCA title and his 2013 Truck runner-up season — established him as a capable multi-series performer within the RCR ecosystem.