The 1991 Pepsi 400 was the 15th stock car race of the 1991 NASCAR Winston Cup Series season and the 33rd iteration of the event.

In the final laps of the race, Melling Racing driver Bill Elliott would manage to mount a late-race charge to the lead, passing for the lead with 13 to go to take his 34th career NASCAR Winston Cup Series victory and his only victory of the season.

On lap 120 of the race, owner-driver Darrell Waltrip, along with RahMoc Enterprises driver Joe Ruttman, would both be involved in a crash on the track's back straightaway.

The standard track at Daytona International Speedway is a four-turn superspeedway that is 2.5 miles (4.0 km) long.

Sterling Marlin, driving for Junior Johnson & Associates, would win the pole, setting a time of 47.286 and an average speed of 190.331 miles per hour (306.308 km/h) in the first round.