There's even the names "Loscy" hanging above the Garden floor, because Jim Loscutoff didn't want his number retired forever.
But there are two men who are honored in the rafters, despite never suiting up for the team. Do you know who they are?
Well, one is Red Auerbach. Though he never so much as hit a free throw for the Celtics, you could say he was pretty important in establishing one of the greatest dynasties in sports. As head coach, Auerbach led the Celtics to nine titles, including eight straight, and he later guided the Celtics as president and general manager.
Despite all those accolades, the number hanging in the rafters to honor him is No. 2.
Do you know who is No. 1? Test your knowledge by trying your hand at the latest installment of NESN Trivia by clicking here.