The 2005 NASCAR Busch Series began with the Hershey's Take 5 300 at Daytona International Speedway and concluded with the Ford 300 at Homestead-Miami Speedway. Martin Truex Jr. of Chance 2 Motorsports was crowned champion for the second consecutive year.
The year saw at least two significant changes:
- The top 30 teams in the previous season's owner points, provided that they attempted all races that season, were guaranteed starting spots in the first five races of 2005. However, only 26 teams met the criteria, so for those races additional spots were available for teams having to qualify on time. After the fifth race, the top 30 teams received the guaranteed starting spots.
- The series ran on the Autódromo Hermanos Rodríguez road course in Mexico City in March. It was the first Busch Series race conducted outside the United States.