Lee played for City for seven years between 1967 and 1974, scoring 148 goals in 330 appearances.
In his first season after joining from Bolton Wanderers, Lee fired City to the league title, their last until 2012.
He also won the 1969 FA Cup and the 1970 League Cup and the European Cup Winners Cup, which was their only continental title until Pep Guardiola's side lifted the Champions League in June. Lee left City in 1974 for for Derby, where he ended up retiring. He later served as City's chairman between 1994 and 1998.
"Franny passed away in the early hours of this morning after a long battle with cancer," City said in a statement. "His wife Gill and children Charlotte, Jonny and Nik say he will be sorely missed and would like to thank everyone for their kind words.
"Everyone at Manchester City would like to send their condolences to the friends and family of Francis at this very difficult time. As a mark of respect, flags around the Etihad Stadium and City Football Academy are flying at half-mast. More tributes from the club will follow in the coming days."
Next Match
Lee won a total of eight trophies throughout his career, six of which came with City. He made 27 appearances for England, scoring 10 goals.