It was announced in September that Ferguson would be awarded with the accolade following his retirement in the summer after 26 years as manager of United, and a formal ceremony took place on Monday.
The 71-year-old has also had Waters Reach, a street adjacent to Old Trafford and overlooking a new statue of Scottish manager, renamed Sir Alex Ferguson Way.
Legendary predecessor Sir Matt Busby has a street named in his honour on the opposite side of the stadium.
It's a great honour, Sir Alex said of the award.
I would like to thank the Borough of Trafford for this wonderful gesture. It is greatly appreciated by me and my family.
The Honourary Freedom is awarded to persons of distinction and persons who have, in the opinion of the Council, rendered eminent services to the Borough’.
Ferguson won 13 Premier League titles and triumphed twice in the Champions League during an extraordinary spell at United that saw him lead the club to 28 trophies over two decades.
