The 2015 FedEx 400 benefiting Autism Speaks was a NASCAR Sprint Cup Series race held on May 31, 2015, at Dover International Speedway in Dover, Delaware. Contested over 405 laps – extended by five laps due to a green-white-checkered finish – on the 1 mile (1.6 km) concrete speedway, it was the 13th race of the 2015 NASCAR Sprint Cup Series season. Jimmie Johnson won the race, his fourth win of the season and tenth at Dover, while Kevin Harvick finished second and Kyle Larson finished third. Kasey Kahne and Aric Almirola rounded out the top five.

The 2015 NASCAR Sprint Cup Series was the 67th season of professional stock car racing in the United States and the 44th modern-era Cup season. The season began at Daytona International Speedway with the Sprint Unlimited exhibition race, the Budweiser Duels, and the Daytona 500. The season ended with the Ford EcoBoost 400 at Homestead-Miami Speedway. Kyle Busch won the championship, despite missing the first third of the season due to severe leg injuries suffered in an Xfinity Series race at Daytona. Busch also became the first Toyota driver to win a Cup championship. Despite not running the full season, Brett Moffitt was named Rookie of the Year.