Keegan was an icon at English giants Liverpool, where he scored 100 goals and provided 88 assists in 322 appearances, winning the Premier League, European Cup, FA Cup and League Cup.
He also played for the German club Hamburg, where he won the Ballon d'Or, the award that at the time went to Europe's best player, twice.
Keegan also played for Southampton and Newcastle, leading the latter club back to the top flight. After his playing career, he also managed Newcastle on two occasions, most recently in 2008.
In the England national team, he won 63 caps and scored 21 goals, and he wore the captain's armband during Euro 1980. As national captain, he led England in Euro 2000, where they were eliminated in the group stage.
Earlier this year, Keegan revealed that he had been diagnosed with cancer and in June he announced that it had spread throughout his body.
Now the family announces that the icon is dead.
"It is with great sadness that we announce the passing of Kevin Keegan after a long illness. The former England international was surrounded by his wife and daughters during the final days of his life," the family wrote in a statement.
"Kevin was not just a footballer or a coach. He was the beating heart of Newcastle for generations of supporters," the football club wrote in a press release.
Kevin Keegan turned 75.
Corrected: In a previous version there was an incorrect wording regarding the Ballon d'Or.
