The 2004 MBNA America 400 was the 28th stock car race of the 2004 NASCAR Nextel Cup Series season, the second race of the 2004 Chase for the Nextel Cup, and the 36th iteration of the event. The race was held on Sunday, September 26, 2004, before a crowd of 140,000 in Dover, Delaware at Dover International Speedway, a 1 mile (1.6 km) permanent oval-shaped racetrack. The race took the scheduled 400 laps to complete. At race's end, Ryan Newman of Penske-Jasper Racing would dominate to win his 11th career NASCAR Nextel Cup Series win and his second and final win of the season. To fill out the podium, Mark Martin of Roush Racing and Jeff Gordon of Hendrick Motorsports would finish second and third, respectively.

The Dover 400 was a NASCAR Cup Series stock car race held annually at Dover International Speedway in Dover, Delaware, from 1971 to 2020. It was the second of two Cup Series races at the 1-mile concrete oval during that time.