Born in Gisland, Northumberland, Freddy hailed from a local Tyneside family which supported Newcastle United for generations and became a director of the club in 1991 after his business success brought him into contact with Sir John Hall.
He took over from Sir John as chairman in 1997, having already played a key role in bringing the likes of Alan Shearer to St. James' Park, and oversaw two FA Cup final appearances and thrilling Champions League campaigns.
Newcastle United managing director Lee Charnley, who worked with Freddy when he was chairman, said: "I was deeply saddened to learn of Freddy's passing today.
"He was an incredibly passionate supporter of Newcastle United and maintained that love for the club even after he stood down as chairman.
"During his time at the club, as both a director and chairman, he had a big part to play in the club's modern-day history and was a driving force in the redevelopment of our stadium and expanding its capacity to more than 52,000.
"He had a huge passion not just for the club, but for the city and region it represents.
"Our thoughts at this time are of course with his family and friends."
The club flag at St. James' Park is flying at half mast as a mark of respect.
A statement from the Shepherd family read: "Freddy Shepherd, former chairman of Newcastle United and chairman of Shepherd Offshore Group and Triple S Sports & Entertainment Group, sadly passed away peacefully at his home last night.
"At this difficult time the family have asked that their privacy be respected."