The 2015 NASCAR Xfinity Series was the 34th season of the NASCAR Xfinity Series, the second-tier professional stock car racing series sanctioned by NASCAR in the United States. It began with the Alert Today Florida 300 at Daytona International Speedway on February 21, and ended with the Ford EcoBoost 300 at Homestead-Miami Speedway on November 21. Chase Elliott entered the 2015 season as the defending series champion. Chris Buescher won the championship. The 2015 season marked two major changes; Comcast's cable brand Xfinity replaced Nationwide Insurance as title sponsor of the series, while Fox, Fox Sports 1, NBC and NBCSN broadcast the series' races, replacing the ESPN networks and ABC.

Stock car racing events in the NASCAR Xfinity Series has been held at the Homestead–Miami Speedway since the track's inauguration in 1995. For much of its history, it was the final race of the second-tier series' season. The event is currently named Contender Boats 300 for sponsorship reasons; with exception of one-off emergency races in 2020 and a one-off change in 2021, the race has been held as a 300-mile race.