The Republic of Ireland international, who was assistant to Jock Stein during Celtic's historic European Cup victory, has passed away, aged 90
Born in Sligo in 1922, Fallon played for several Irish clubs including Sligo Rovers before joining Celtic in 1950, where he went on to make over 250 appearances for the club.
Capped eight times by the Republic of Ireland, Fallon eventually went on to become assistant manager to Jock Stein at Celtic Park, where he was a part of the historic European Cup success in 1967, when the Hoops defeated Inter in the final.
"Sean Fallon was a Celtic legend who devoted much of his life to the club he loved," Celtic chief executive Peter Lawwell said. "He was, of course, a supporter, first and foremost, and he was proud to have worn the green and white hoops that he loved.
"He did so with fearless distinction over eight years in the 1950s, and Sean was at the heart of all of our triumphs, including that famous 7-1 League Cup victory in 1957."
He continued: "Ten years later, he was part of our greatest ever success, winning the European Cup in Lisbon. "Working alongside Jock Stein, Sean helped to deliver that trophy, along with nine consecutive league titles and numerous other trophies.
"He was a gentleman with a great sense of humour, and always a welcome guest here at Celtic Park. And there could have been no more fitting person to unveil the championship flag at this start of this, our 125th anniversary season, than a man who gave so much to Celtic Football Club.
Current Celtic boss Neil Lennon also paid tribute to Fallon, describing him as 'a great Celtic man'.
He said: "We are all shocked and saddened to hear of Sean's death, and the thoughts of all the players and management are with his family.
"Sean was a great Celtic man, and it's been a privilege to meet him over the years. He was always a very humble man when you met him, even though his achievements in the game were extraordinary.
"He did everything you could ever wish to achieve in football, as a player for both club and country, while he went to even greater things in management alongside Jock Stein.
"For these things, the Celtic supporters have always loved Sean and recognised him as one of our own because it was always his great love of Celtic which shone through.
"It was a fitting tribute that Sean unveiled the championship flag back in August and the welcome he received from the supporters spoke volumes. We will all miss him."