"It is with a heavy heart that we must announce that the greatest winner in American sports history has passed away peacefully with his wife Jeanine by his side," the family wrote on Twitter.
With the Boston Celtics, Russell won eleven NBA titles in 13 years.
The latter two as playing coaches, thus becoming the first black person to lead a team in one of the major American sports.
Along with ice hockey player Henri Richard, Russell shares the record for most titles in a major league in a professional American team sport.
“He paved the way for all the black players who came after him, myself included.
The world has lost a legend," said six-time NBA champion Michael Jordan in a statement.
In addition to his basketball exploits, Russell stood up for the rights of black people.
Before an exhibition game at Kentucky in 1961, restaurant staff refused to serve the black players in Boston.
Led by Russell, they then refused to play the match and went home.
“For decades, Bill was subjected to insults and vandalism, but he never let that stop him from speaking out for what was right.
I learned so much from the way he played, the way he coached and the way he lived his life," former US President Barack Obama wrote on Twitter.
Russell stood up for boxer Muhammad Ali when he refused to join the army for religious reasons and marched with Martin Luther King during the iconic "I have a dream" speech in 1963. Russell was also active in the Black Power movement.
In 2011, Russell was awarded the Presidential Medal of Freedom by Barack Obama for his fight for black people's rights.
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Photo: TT