The 59-year-old was killed in a crash on the Old Military Road near to Castle Douglas on Wednesday.
Emergency services were sent to the location at about 23:30 but the man - who was riding a black Triumph bike - had died at the scene.
The road was closed for about five hours to allow for collision investigations to take place.
PC Hazel Smyth said: "We are carrying out a full crash investigation into this collision and would ask that anyone who may have witnessed this RTC get in touch with us.
"We are particularly keen to speak with anyone who may have travelled the Old Military Road between 16:30 and 23:30 on Wednesday."
A motorcyclist has died in an accident on a minor road in Dumfries and Galloway.