Dr Martin Kirkbride, a geographer from the University of Dundee, used a technique called cosmogenic 10Be dating to determine that the glacier was in the Cairngorms as recently as the 18th century. His research provides new evidence, which supersedes previous theories that Britain's last glaciers melted around 11,500 years ago.
He said: "The climate of the last few millenia was at its most severe between 1650 and 1790.
"There are some anecdotal reports from that time of snow covering some of the mountain tops year-round. What we have now is the scientific evidence that there was indeed a glacier."
Dr Jez Everest, of the British Geological Survey in Edinburgh, said: "This has great importance when we start to reconstruct climate change in Scotland and the wider region over the last few centuries."