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."

The moneyed men were from the town's trawling fleets and made their living working "at the hardest job in the world".
After about three weeks toiling in the fishing grounds, they would return for just three days on land to spend their hard-earned cash before going back to sea.
Their lives and other aspects of the booming Grimsby fishing industry of the 1950s are being marked in an exhibition called Fish, Ships and Rock 'n' Roll.
Local history enthusiast Alf Ludlam, 71, said: "The men would stand out in what almost amounted to a uniform.
"They would wear pale grey or blue suits with lots of pleats in the back of the jackets and baggy trousers."
Mr Ludlam, a museum volunteer with Grimsby Council, said the suits were a fashion statement but also a way of saying "look at my money" because the trawlermen could afford to buy a extravagant quantity of cloth.
And the men wore open-necked shirts as "however cold it was in town, it was never as cold as on a trawler off Iceland," he added
Mr Ludlam remembers watching the men roaming his home town during the 1950s, a time when "thanks to fishing Grimsby was making more money than ever".
At its peak in that decade, Mr Ludlam said Grimsby was "the largest fishing port in the world".
The vibrancy of the fishing trade had a spin-off for the rest of the town until the mid-1970s. It was a great period to grow up in Grimsby, Mr Ludlam said, because "everything was in the melting pot".
"Fishing was Grimsby's raison d'etre - no fishing, no Grimsby, " he added.
The heyday for the trade lasted about 20 years but the reliance on fishing proved to be a problem for the town as the trawler fleet contracted during, and after, the two decades of the Cod Wars.
Iceland started extending its territorial limit around the island to exclude foreign vessels from the water it claimed as its own.
The limit was extended on three occasions between 1958 and 1976, each time forcing British fishing vessels further offshore.
The limit was finally extended 200 miles off Iceland.
This led to confrontations at sea between the Icelandic coastguard and trawlers from Grimsby and Hull.
Several ships were even rammed as trawlers continued to try to fish within the new limit.
The neighbouring fishing ports of Grimsby and Hull vied with each other in the size and skill of their trawler fleet, and the quality and quantity of fish landed.
Mr Ludlam said the ports had "always been at daggers drawn" and their fishing fleets were a source of civic pride.
He said the collapse of the trawler industry in Grimsby mirrored the similar economic and social struggle former mining towns experienced after the pits closed.
The two industries of fishing and mining were also linked by the level of danger encountered.
Mr Ludlam said: "Fishing was the most dangerous - when you set sail you didn't know if you were going to come back."
The free exhibition Fish, Ships and Rock 'n' Roll is open until Sunday January 13 at the Fishing Heritage Centre in Grimsby
A motorcyclist has died in an accident on a minor road in Dumfries and Galloway.
[NEXT_CONCEPT]
It was easy to spot a so-called "three-day millionaire" in Grimsby in the 1950s.