Four other directors, including Aberdeen Asset Management pair Martin Gilbert and Hugh Little, are to leave the Pittodrie board.
Gilbert and Little will depart once AAM's shares in the club are transferred 'to other individuals', says STV reporter Tyrone Smith on Twitter.
This is a major upheaval for Aberdeen, as Aberdeen Asset Management is the majority shareholder in the club.
Ken Matheson and fans representative Chris Gavin are leaving the Aberdeen board with immediate effect.
And the club has appointed George Yule as the new Executive Vice Chairman.
Chairman Stewart Milne said Mr Yule, the president of Grampian Chamber of Commerce, will be a “welcome and necessary addition to the club” when he arrives at Pittodrie on July 1 to work alongside chief executive Duncan Fraser.
He said: “I am extremely pleased that George, who has a wealth of contacts and experience in all sectors has agreed to come on board at this absolutely crucial time in our history. I believe his enthusiasm, experience and judgement will add focus and momentum to the future direction of the club.
"We need a step-change in how the club is run if we are to deliver our vision of delivering the new stadium and soccer academy, and be in a position to take full advantage of these fantastic new facilities when we move.
"At the same time we will be pushing forward our plan to achieve substantial growth over the next three years, and George will play a pivotal role in bringing about this step change.
"It is testament to Duncan’s ability that he has managed so well for so long, but any other business would not be relying on one senior executive to deal with the pressing day to day issues as well as planning for and managing the future in what is a very challenging environment, and nor can we.
"Duncan will continue to oversee the day to day running of the football and non-football aspects of the club, and represent us at SPL level where I believe he will play a major role as Scottish football goes into a period of fundamental change. I strongly believe Aberdeen Football Club must play a significant role in this period of uncertainty.
"George and Duncan working together will give us an exceptionally strong executive team."
Mr Milne added: "Aberdeen Asset Management (AAM) has been a tremendous supporter of the club for a great number of years but, with the organisation’s focus on its core asset management business, feel that the involvement in AFC has reached a natural conclusion.
"They will however continue to support the club. AAM’s shares in the club meantime will later be transferred to other individuals predominantly the new board members and Martin and Hugh will step down following the completion of those transactions.
"I would like to publicly thank AAM for the substantial contribution the company has made to this club, as it has been absolutely crucial over a very challenging period.
"Ken and Chris both indicated their intentions to step down some time ago and their input over a considerable period of time has been invaluable. Ken’s experience in corporate banking has assisted the club through the difficult conditions in that sector. Chris has given real input and was instrumental in setting up the AFC Former Players Association.
"Chris has agreed to continue to assist the club with supporters' groups and George Yule and Ian Jack will also be centrally involved in supporter issues. Chris will also continue to play a significant role in the AFC Heritage Trust, which he helped set up.
"Clubs have always faced challenges which vary in nature and gravity, none more so than what lies ahead over the next few years. We have an obligation to our supporters, shareholders and all those associated with the club to ensure we are fit for the future, and have the best resources available to us. We believe George’s appointment as executive vice chairman does exactly that.
"Moving forward, the streamlined board comprising Duncan Fraser, Gordon Buchan, Ian Jack, George Yule, Colin Welsh and myself incorporates, I believe, the skill sets, the drive and ambition required to ensure the successful delivery, both on and off the park, that our fan base quite rightly demands."