The 2004 NASCAR Nextel Cup Series was the 56th season of professional stock car racing in the United States and the 33rd modern-era Cup series season. The season began on Saturday, February 7, and ended on Sunday, November 21. Kurt Busch, who drove a Ford for Roush Racing, was the Nextel Cup champion. It would be the last time until 2012 that the championship would be won by someone other than Tony Stewart or Jimmie Johnson.

Kurt Thomas Busch is a former American auto racing driver. He last competed full-time in the NASCAR Cup Series in 2022, driving the No. 45 Toyota Camry TRD for 23XI Racing. He is the 2004 NASCAR Cup Series champion and the 2017 Daytona 500 winner. He is the older brother of two-time Cup Series champion Kyle Busch.