Bonhams, who will auction the collection on October 20 under instruction from the executors of his estate, say the guide price for the medal will be between 90,000 and 120,000 pounds.
Best, who died aged 59 in 2005 after a long battle with drink and its associated health problems, was part of the United team became the first English side to win the European Cup, scoring one of the goals in a 4-1 victory over Benfica.
The auction will also include a replica of the European Cup winners' medal which was made after he misplaced the original.
Collectors will also be able to bid for Best's 1968 English Football Writer's Association Footballer of the Year trophy which is expected to fetch up to 100,000 pounds.
The total amount expected to be raised from the collection, which also contains a limited edition George Best Faberge egg to commemorate his part in the European Cup triumph, is estimated at around 270,000 pounds.
Belfast-born Best made 470 appearances for United between 1963 and 1974, scoring 179 goals, but after leaving the Old Trafford club his glittering career went into decline as his celebrity lifestyle began to take its toll.
His final years were marked by health problems, including a liver transplant.
