The incident occurred on the B7085 road near Whauphill, Newton Stewart at around 11.50 am.
The cyclist, a 31 year old man from Minnigaff was knocked from his cycle as a result of the collision and was treated for minor injuries by ambulance staff at the scene.
Constable Rachel Jackson at Newton Stewart said: “The driver of the tractor did not stop after the crash and continued on southwards towards Whauphill.
“We would appeal for him or her to come forward to police at Newton Stewart.
“The tractor is described as being red and black in colour and was towing a silver coloured Joskin trailer. Anyone who can help us trace this vehicle is asked to call police at Newton Stewart on 101.”
