William Byron (racing driver)

NASCARO'Reilly Auto Parts Series career46 races run over 6 yearsCar no., teamNo. 88 (JR Motorsports)2025 position77thBest finish1st (2017)First race2017PowerShares QQQ 300 (Daytona)Last race2026MillerTech Battery 250 (Pocono)First win2017American Ethanol E15 250 (Iowa)Last win2025BetMGM 300 (Charlotte)NASCARCraftsman Truck Series career31 races run over 6 years2025 position79thBest finish5th (2016)First race2015Lucas Oil 150 (Phoenix)Last race2025Heart of Health Care 200 (Kansas)First win2016Toyota Tundra 250 (Kansas)Last win2022Blue-Emu Maximum Pain Relief 200 (Martinsville)ARCA Menards Series career4 races run over 2 yearsBest finish58th (2016)First race2015Sioux Chief PowerPEX 200 (IRP)Last race2016General Tire #AnywhereIsPossible 200 (Pocono)ARCA Menards Series East career14 races run over 1 yearBest finish1st (2015)First race2015Hart to Heart Breast Cancer Foundation 150 (New Smyrna)Last race2015Drive Sober 125 (Dover)First win2015Kevin Whitaker Chevrolet 150 (Greenville-Pickens)Last win2015United Site Services 70 (New Hampshire)ARCA Menards Series West career3 races run over 2 yearsBest finish32nd (2018)First race2015Carneros 200 (Sonoma)Last race2018Carneros 200 (Sonoma)Statistics up to date as of September 19, 2026.

William McComas Byron Jr. (born November 29, 1997) is an American professional stock car racing driver. He competes full-time in the NASCAR Cup Series, driving the No. 24 Chevrolet ZL1 for Hendrick Motorsports, and part-time in the NASCAR O'Reilly Auto Parts Series, driving the No. 88 Chevrolet SS for JR Motorsports.

Byron won the 2015 NASCAR K&N Pro Series East Championship and the Rookie of the Year award in the 2016 NASCAR Camping World Truck Series season. The following season, he won both the 2017 NASCAR Xfinity Series Championship and the 2017 Sunoco Rookie of the Year. He also won the 2018 NASCAR Cup Series Rookie of the Year award. He is the 2024 and 2025Daytona 500 winner, and the 2025 NASCAR Cup Series Regular Season Champion.