Riley D. Herbst[1] (born February 24, 1999) is an American professional stock car racing driver. He competes full-time in the NASCAR Xfinity Series, driving the No. 98 Ford Mustang for Stewart-Haas Racing and part-time in the NASCAR Camping World Truck Series, driving the No. 17 Ford F-150 for David Gilliland Racing.

Herbst began racing karts as a five-year-old.[2] He progressed through legends, Speed Trucks, and Super Late Models.[2] In 2015, he raced weekly at Irwindale Speedway in a Super Late Model as well as winning the track's Speed Trucks championship.[

In 2016, he raced several NASCAR East and West series races along with racing a Super Late Model at Irwindale.

Herbst is from a family rooted in off-road racing. His father Troy, grandfather Jerry, and uncles Ed and Tim participate in desert racing such as the Baja 500 and Baja 1000.[2][3] The quartet was inducted into the Southern Nevada Sports Hall of Fame in 2014

In 2017, Herbst drove full-time for Joe Gibbs Racing in the No. 18 Toyota in the ARCA Racing Series. He drove the No. 81 in the first race but withdrew due to age limitations. He then moved to the No. 18 for the rest of the season.

In 2020, he joined his cousins Pierce and Thor at the 2020 Baja 1000, where they finished second in the Trophy Truck Spec class.[6] The trio also ran the 2021 1000 and placed ninth.

In May 2018, Herbst was named to the 2018 NASCAR Next class.[3] In June 2018, Herbst joined JGR for his NASCAR Xfinity Series debut at Iowa Speedway. For the 2019 season, he split JGR's No. 18 with Jeffrey Earnhardt, Kyle Busch, and Denny Hamlin

He said all of them "have gone through rigorous reviews and vetting to ensure they meet all the necessary protocols prior to a medication being dispensed via standing order."

In 2020, Herbst assumed full-time driving duties in the No. 18. He qualified for the playoffs but was eliminated following the first round.[14] He ended the year with a 12th-place points finish, four top-five finishes, 17 top tens, and a best finish of second at Auto Club Speedway and Kentucky Speedway

On December 10, 2020, Stewart-Haas Racing announced Herbst would drive the No. 98 Ford beginning with the 2021 season. After a rough start to the season that saw his involvement in wrecks—none of which were of his doing—in three of the first four races