The 2019 NASCAR Xfinity Series was the 38th season of the NASCAR Xfinity Series, a stock car racing series sanctioned by NASCAR in the United States. Tyler Reddick entered as the defending champion, and won his second championship over Cole Custer and Christopher Bell, who were known as "the big three" over the course of the season as they dominated the vast majority of the races. Reddick also clinched the 2019 Regular Series Championship following the 2019 Rhino Pro Truck Outfitters 300 at Las Vegas Motor Speedway. Reddick became the first back-to-back champion to drive for two different teams (JR Motorsports in 2018 and Richard Childress Racing in 2019).