Sam Mayer

Early career

Mayer got off to an early start in racing, competing in go-kart events at the age of four. Although his father, Scott Mayer, was an open-wheel racer, Sam chose in his preteen years to focus on stock car racing. Over the course of the 2017 summer, during which Mayer turned fourteen, he spent the summer in Charlotte to race Legends cars; he won the Young Lions division of the Charlotte Motor Speedway Summer Shootout. He also raced in a Limited Late Model and won at Greenville-Pickens Speedway to become the track's youngest winner. He came back to Wisconsin and won a September Midwest Truck Series race at Dells Raceway Park in his first series start.

In 2017, Mayer came in touch with industry veteran Lorin Ranier, who eventually landed Mayer a late model ride with JR Motorsports in the CARS Tour for 2018. Mayer's late model racing also brought him to the World Series of Asphalt, where he finished second to Stephen Nasse. After the CARS Tour season was over, Mayer was voted the series' Most Popular Driver for 2018. The CARS Tour season included one victory, at Wake County Speedway.

ARCA Menards Series

Ranier also led Mayer to MDM Motorsports for a limited slate in the ARCA Racing Series and NASCAR K&N Pro Series East in the back half of 2018, with age restrictions being a factor in which races Mayer could run, as both series only let fifteen year old competitors race on certain tracks. In his first ARCA race, Mayer ran as high as third and finished inside the top-ten.

On December 5, 2018, it was announced that Mayer would run a full NASCAR K&N Pro Series East schedule with GMS Racing as part of a 2019 schedule that would also include seven ARCA races.

Mayer scored his first K&N East win at Bristol on April 6, 2019, leading every lap. He nearly scored his first ARCA Menards Series win at Gateway in June after a late pit gamble, but was moved up the track by Ty Gibbs in the final set of corners and was relegated to third. In October, he won the 2019 K&N East championship to become the youngest NASCAR champion at 16 years, 3 months, and 8 days; the previous record was 16 years and 5 months by Todd Gilliland in 2016. Mayer ended the 2019 season with four wins and top tens in all but one race.

Mayer raced in the ARCA Menards Series and ARCA Menards Series East in 2020. An injury at Road America forced Colin Braun to sub in for Mayer midway through the AMS race at the Daytona International Speedway road course. Mayer later won ARCA's first trip to Lebanon I-44 Speedway. Mayer also won at Bristol. He overcame a pit miscue to claim the checkered flag in the ARCA event. Mayer won the East finale at Five Flags Speedway to capture the series championship with an average finish of 1.2 on the season.

In 2021, Mayer would also drive select races in Bret Holmes Racing's No. 23 car in the ARCA Menards Series and ARCA Menards Series East.

In 2024, Mayer driving for Sigma Performance Services, made a one-off start in the ARCA Menards Series West at Sonoma and would take the lead from William Sawalich in the middle stages of the race, and led the final 37 laps to earn his second career West Series win.

NASCAR Gander Outdoors Truck Series

Mayer made his NASCAR Gander Outdoors Truck Series debut in 2019 with GMS Racing in four events, the four races came after Mayer turned sixteen. He made his debut at Bristol Motor Speedway, where he was placed in the 21st position, a DNF. That race would be followed by appearances at Martinsville Speedway and ISM Raceway. In 2020, Mayer made six starts, and he won at Bristol after winning the ARCA race hours before.

On January 14, 2021, defending ARCA champion Bret Holmes announced he would begin fielding a part-time Truck Series team, the No. 32, for himself and Mayer for the upcoming season. Three days later on January 17, it was also announced that Mayer would run seven races in the No. 75 for Henderson Motorsports in the Truck Series, beginning at the Daytona Road Course, which would end up being his only start with Henderson.

NASCAR O'Reilly Auto Parts Series

On September 15, 2020, Mayer and JR Motorsports announced an agreement to have him drive one of the organization's NASCAR Xfinity Series cars part-time in the latter portion of 2021 and full-time in the 2022 season.

On January 4, 2022, it was confirmed that Sam Mayer would drive the JR Motorsports No. 1 in 2022, replacing Michael Annett. At the Martinsville spring race on April 8, Mayer finished fifth after doing a bump and run on Ty Gibbs on the final lap. After the race, Gibbs attempted to spin Mayer out during the cool-down laps before both drivers engaged in a fistfight on pit road. Mayer would go on to finish seventh in the final points standings with a best result of second at Talladega.

On August 9, 2022, it was announced that Mayer would return for the 2023 season. He started the 2023 season with a 27th-place finish at Daytona, where he flipped down the backstretch on the final lap. Mayer scored his first career win at Road America. He followed it up with his second win at Watkins Glen. During the playoffs, Mayer won at the Charlotte Roval and at Homestead to make the Championship 4. Mayer finished fifth at Phoenix and third in the points standings.

Mayer started the 2024 season with a 36th-place DNF at Daytona. At Texas, he scored a narrow victory over Ryan Sieg at Texas by 0.002 seconds, making it part of a three-way tie for the second closest finish in Xfinity Series history. Mayer scored his second win of the season at Iowa. During the playoffs, he was disqualified at Talladega after his car failed the post-race ride height requirement. A week later, Mayer won at the Charlotte Roval.

On August 17, 2024, Mayer signed with Haas Factory Team to drive the No. 41 Ford in 2025. Mayer started the season with a second-place finish at Daytona. After staying consistent throughout the year, he won at Iowa, earning Haas's first win in their career and the first win for Ford that year.

On October 28, 2025, NASCAR imposed a one-race suspension on Mayer for intentionally wrecking Jeb Burton during the post-race cooldown lap at Martinsville, with Ryan Sieg replacing him for the season finale at Phoenix.

Mayer started his 2026 season with a 31st place DNF at Daytona. He won the pole at both Atlanta races and spring Las Vegas race.

On September 22, 2026, Mayer signed with JRM to return to the No. 1 Chevy in 2027.

Other racing

In 2020, Mayer made a TA2 Trans-Am start at Road America and suffered a hairline fracture in his wrist during a race-ending crash.

Mayer's father Scott Mayer, also a race driver, is the founder of QPS Employment Group and Accelerate Professional Talent Solutions, Mayer's primary sponsor in the Xfinity Series. As of 2023, the company has 57 branches across eight states and employs thousands of associate employees, making it one of the largest employment firms in the Midwest.

Racing career summary

^† As Mayer was a guest driver, he was ineligible for championship points.

NASCAR

(key) (Bold – Pole position awarded by qualifying time. Italics – Pole position earned by points standings or practice time. * – Most laps led. ** – All laps led.)

O'Reilly Auto Parts Series

Camping World Truck Series

^* Season still in progress
¹ Ineligible for series points

ARCA Menards Series

(key) (Bold – Pole position awarded by qualifying time. Italics – Pole position earned by points standings or practice time. * – Most laps led.)

ARCA Menards Series East

ARCA Menards Series West

CARS Late Model Stock Car Tour

(key) (Bold – Pole position awarded by qualifying time. Italics – Pole position earned by points standings or practice time. * – Most laps led. ** – All laps led.)