In a statement Friday, Cubs Chairman Tom Ricketts praised Santo for "his passion, his loyalty, high great personal courage and his tremendous sense of humor."
WGN reports that Santo died in an Arizona hospital from complications of bladder cancer. Santo was diagnosed with diabetes when he was 18 and later lost both legs to diabetes.
Santo was a nine-time all-star in his 15-year career. The third baseman was widely regarded as one of the best players never to gain induction into the Hall of Fame.
Ricketts says that Santo will always be "the heart and soul of Cubs fans" and the team plans to celebrate his contributions in the days ahead.