The cyclist came off his bike around 1.30pm and suffered injuries.
A call was made to both the emergency services including the Donegal Mountain Rescue Team.
Members of the DMR team reached the man and stretchered him back to a main road.
He was then transferred to the ambulance where he was taken to Letterkenny General Hospital.
The Donegal Mountain Rescue Team were stood down a short time later.
The extent of the cyclist’s injuries are not known at this stage.
A spokesman said “We understand the person suffered injuries when they came of the bike but we do not know how serious they are.
“The person was taken to Letterkenny General Hospital where they are being assessed.”