Glas-bheinn Mhor is a Graham of 650.6 m in Highland. Its drop clears the 150 m Marilyn standard by only 6 m.
It is the lowest of the 12 register hills in the Glen Affric to Glen Moriston region, where A' Chraileag is highest. On the Grahams height ladder it sits between Beinn Donachain (651.4 m) and Sgorr Mhic Eacharna (650.5 m). It is 215.1 m below the average height of the 427 register hills in Highland.