The Boston Symphony Orchestra (BSO) is an American orchestra based in Boston, Massachusetts. It is one of the country's five major symphony orchestras commonly referred to as the "Big Five". Founded in 1881, the BSO plays most of its concerts at Boston's Symphony Hall and in the summer performs at Tanglewood.

Andris Nelsons is scheduled to serve as the music director designate of the BSO in the 2013-2014 season, and to become music director with the 2014-2015 season. Bernard Haitink currently holds the title of conductor emeritus of the BSO, and Seiji Ozawa has the title of BSO music director laureate.