Baizley battled non-smoker's lung cancer, and his death brought an outpouring of support from the hockey community.
"Saddened to hear of Don Baizley's passing," fellow agent Allan Walsh wrote on Twitter. "He defined integrity and honour. Heaven just got one helluva sports agent."
Baizley represented a number of prominent stars, including Selanne, Forsberg, Joe Sakic, Paul Kariya, Theo Fleury and Saku Koivu.
He was a mediator during the 2004-05 NHL lockout and was considered one of the most influential men in the sport.
"Agents rarely compliment one another," fellow agent Alec Schall tweeted. "Don Baizley was respected by all. I started off revering his client list and came to revere the man."
Edmonton Oilers star Jari Kurri signed on with Baizley when he was 20 years old. Baizley had a good reputation from working with Finnish players, but Kurri almost immediately trusted him because of the way he conducted himself.
"Coming from another country, you can't have it better than having Don handle your things and give you advice," Kurri said from Finland. "What an amazing (man) he was."
The Winnipeg native was a member of the Manitoba Hockey Hall of Fame based on his 30 years of experience in the game that included two years as a player in the Manitoba Junior Hockey League.
"Don Baizley was one of the truly unique individuals in our game," Jets general manager Kevin Cheveldayoff said in a statement. "He was loyal, humble and so well-respected. He was honest yet fair and a true gentlemen in what can sometimes be difficult circumstances. While everyone associated with the National Hockey League will feel sadness today, we at the Winnipeg Jets are experiencing a huge loss because of the personal relationships he had with so many in our organization and our city."
Baizley's death was confirmed by a fellow agent who didn't want to be quoted.