The 2026 NASCAR Cup Series marks the 78th season of professional stock car racing, kicking off with the Daytona 500 on February 15 and concluding at Homestead-Miami Speedway on November 8, with Kyle Larson returning as defending champion and Denny Hamlin clinching the top seed in the revived "Chase" playoff format. The season was tragically overshadowed by the death of two-time champion Kyle Busch on May 21 from sepsis caused by pneumonia, making him the first active full-time driver to die during a season since Dale Earnhardt in 2001. In his honor, Richard Childress Racing retired the No. 8 car (holding it for Busch's son Brexton) and renumbered it to 33, with Austin Hill named as his permanent replacement. Off the track, Chevrolet introduced a new ZL1 body style, teams like Haas Factory Team and Rick Ware Racing switched to Chevrolet, and Daniel Suárez moved to Spire Motorsports while Connor Zilisch became the only full-time rookie. Rule changes included a horsepower increase to 750 at shorter tracks, a new superspeedway package, and a lowered minimum age of 17 for the O'Reilly Auto Parts Series, reflecting NASCAR's efforts to modernize competition and safety.