Young joined City in 1959 as an apprentice and went on to play an integral role in the club's glory years, during the late 1960s and early 1970s.
He will be best remembered for scoring the winning goal in the 1969 FA Cup final defeat of Leicester.
City said on their official website, www.mcfc.co.uk: "Quiet and shy away from the game, he rarely visited the club in his later years, though still followed the Blues' progress keenly. He will be sadly missed by his wife Carmen, family, friends and everyone connected with Manchester City."
Born and raised locally in Fallowfield, Young finished top scorer for City in their title-winning season of 1968, netting twice in the 4-3 title-clinching victory at Newcastle on the final day of the campaign.
He also scored for the club he supported as a boy as City won the 1970 European Cup Winners' Cup.
Young excelled alongside Francis Lee, Colin Bell, and Mike Summerbee but failed to win any England caps.
When first-team opportunities became fewer, he left Maine Road in 1972 after scoring 107 goals for the club in 412 appearances and signed for Preston North End. He retired after a brief spell at Rochdale in 1974-75. Young was inducted into the Manchester City Hall of Fame in 2008 in acknowledgement of his services to the club.
After news of his illness became known, City fans paid tribute to Young during the recent 2-2 draw with Leicester in the FA Cup third-round when they celebrated throughout the 24th minute of the match to commemorate Young's Wembley winner at the same point as the game from 42 years ago.
Many fans were also decked out in the red and black colours City wore in the 1969 cup final, a gesture reciprocated by the club's players ahead of the 4-2 replay victory at Eastlands by wearing replica red and black shirts with Young's name on for the pre-match handshakes.