The club announced they had "come to an agreement, whereby they will part ways, effective from today".
The statement added: "Chairman Roy MacGregor wishes to recognise the contribution both have made to the journey that Ross County FC have made over their years with the club and wish both well in their future careers.
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"Further details of the club's continuing restructuring will be made available as plans are ratified over the following days."
After a large turnaround of players in the summer, County had lost their opening four Scottish Premiership matches of the season before beating Stranraer 2-1 in the League Cup on Tuesday night.
But Derek Adams had turned round their form in County's previous two top-flight seasons, achieving a fifth-place finish in 2013 and seventh spot last term.
The former Motherwell and Aberdeen midfielder was in his second spell as County boss, having a brief spell as Hibernian assistant manager in between.
The 39-year-old, who also had two playing spells with the Dingwall club, led County to two promotions and the 2010 Scottish Cup final, where they lost to Dundee United.
Adams senior joined the club in 2005 as director of football, a position County are now set to dispense with entirely.
He had formerly been a key figure in the youth development departments of Aberdeen, Motherwell, Celtic and Rangers, working closely with Sir Alex Ferguson during his time at Pittodrie.
The news was announced as media gathered for the usual Thursday morning preview press conference ahead of County's visit to Hamilton on Saturday. The Adams family had been told of the board's decision on Wednesday night.
MacGregor said: "In the life of football clubs, sometimes change needs to happen. In the life of Ross County we just feel that change for a number of reasons has had to be made.
"On a personal basis, it's probably been the most difficult decision I've made in football. Not only were Derek and George personal friends, they gave the club so much history.
"In many ways the club wouldn't be where it was today if it wasn't for the contribution of those two gentlemen."
The chairman added: "So to think a change needed to be made was a fairly serious situation, but we feel in the interests both on and off the park, this was the right time to make a change."
Assistant manager Steven Ferguson, who replaced Neale Cooper in the summer, will take the team at New Douglas Park.
Adams released a statement this afternoon following his departure from the club.
He said: "I am very proud to have represented Ross County as a player and manager in my career. I would like to thank all of the players who have worked with me, my coaching team and all staff at the club and I would like to thank the Board and the Chairman for the opportunity to have the honour of working with Ross County and of course the supporters and the local community for their support and for the part they have played in the incredible journey we have taken as a club.
"During my time at the Club, I have watched with immense pride as Ross County has grown from the Scottish Second Division through two promotions to the Scottish Premiership, where we are now in our 3rd season. The fact we achieved this progress while setting an unbeaten record in Scottish league football for the modern era of 40 matches* and reaching a Scottish Cup Final along the way gives my coaching team and myself great satisfaction.
"Considering the fact that Ross County has had I believe one of the lowest, if not the lowest, wage bills in the league in the last couple of seasons, I believe this shows our 'David' has notched victories against the 'Goliaths' of Scottish football more often than we might have reasonably expected. This is most clearly demonstrated by our victories against Celtic, especially in the Scottish Cup Semi Final when at that time we were a First Division side.
"As part of the financial realities of working at Ross County, I have become accustomed to working in a challenging environment. For the last few seasons, while working with a low wage budget we have had to build almost entirely new teams to start each season without ever spending a transfer fee which has been a massive challenge that we have been able to meet by retaining our Premiership status. While this has been extremely challenging, I believe it makes the journey we have taken even more remarkable and I am very proud to have been a part of it.
"I have always believed that the test of a manager is in consistently outperforming his resources and I believe I achieve that with Ross County.
"I would like to thank the players, the fans, my management team and all the staff, the chairman and the board and everyone associated with Ross County football club and wish them every success for the future."