New Bulls coach Tom Thibodeau, formerly a Boston Celtics assistant, wanted Scalabrine and pushed hard for him with Bulls general manager Gar Forman and vice president John Paxson.
Scalabrine, 32, spent five years with the Celtics and had limited playing time last season. He averaged 3.3 points and 2.1 rebounds a game in nine seasons with the Celtics and New Jersey Nets and made four trips to the NBA Finals, including a title-winning campaign with Boston in 2008.
Yahoo Sports was first to report the signing.
Nick Friedell covers the Bulls for ESPNChicago.com and ESPN 1000.