Assistant manager Gerry Taggart, fitness coach Paul Butler and first-team coach Lee Duxbury have all been told they do not feature in the club's plans, and have been put on gardening leave.
Manager Paul Dickov has kept his job and will be in charge at Glanford Park, assisted by goalkeeping coach Paul Gerrard - whose long-term future at the club "will be considered at a later date".
"We appointed Paul Dickov in June, 2010 and it has been a vast learning curve for him. He has received mine and the board's support along the way because we believe that we have the right man on board," said Simon Corney, the Oldham chairman.
"However, in recent times we, as a board, are unanimous in the belief that the chemistry of our backroom team and coaches is not right and this has been discussed with Paul in depth.
"I thank those members of staff who are leaving for their commitment and support in the past, but believe that changes are necessary for the good of the club."