Wood Brothers Racing is an American professional stock car racing team that currently competes in the NASCAR Cup Series. The team was formed in 1950 by brothers Ray Lee, Clay, Delano, Glen, and Leonard Wood. Today, it is owned by the children and grandchildren of Glen Wood -- Len Wood, Eddie Wood, Kim Hall, Jon Wood, Jordan Hicks, and Keven Wood. From 2006 to 2008, the team was merged with Tad and Jodi Geschickter's JTG Racing. The Wood Brothers Racing Team holds the unique distinction of being the oldest active team in NASCAR, having fielded cars since 1950. They are known for their long relationship with Ford Motor Company, and the long-standing use of the number 21 on their main car. The team currently fields the No. 21 Ford Mustang full-time for Harrison Burton and has a technical alliance with Team Penske.

The NASCAR Cup Series is the top racing series of the National Association for Stock Car Auto Racing (NASCAR). The series began in 1949 as the Strictly Stock Division, and from 1950 to 1970 it was known as the Grand National Division. In 1971, when the series began leasing its naming rights to the R. J. Reynolds Tobacco Company, it was referred to as the NASCAR Winston Cup Series (1971–2003). A similar deal was made with Nextel in 2003, and it became the NASCAR Nextel Cup Series (2004–2007). Sprint acquired Nextel in 2005, and in 2008 the series was renamed the NASCAR Sprint Cup Series (2008–2016). In December 2016, it was announced that Monster Energy would become the new title sponsor, and the series was renamed the Monster Energy NASCAR Cup Series (2017–2019). In 2019, NASCAR rejected Monster's offer to extend the naming rights deal beyond the end of the season. NASCAR subsequently announced its move to a new tiered sponsorship model beginning with the 2020 season similar to other U.S. based professional sports leagues, where it was simply known as the NASCAR Cup Series, with the sponsors of the series being called Premier Partners. The four Premier Partners are Busch Beer, Coca-Cola, GEICO, and Xfinity.