Orthetrum glaucum is a large size blue dragonfly species. It looks alike O. triangulare. However, it is more common than O. triangulare although both O. glaucum and O. triangulare triangulare are widespread. O. glaucum can be distinguished from O. triangulare triangulare by the smaller patch of dark amber at the base of the hind wing and narrower abdomen in both sexes. For mature male, the black tip of the abdomen is less extensive in O. glaucum (usually not beyond the 8th abdomenal segment) than in O. triangulare triangulare. The color of the thorax of male O. glaucum becomes pruinosed pale blue with age while that of O. triangulare triangulare is black. As the color of both male and female of these species vary with age, it may be hard to distinguish them by color alone. Besides, subadult male and female of these species also look similar.

The male is a fairly big dragonfly that once fully mature becomes pruinosed (a bit like the felt-look of a peach). It is almost entirely blue. They are quite easily scared, but seem to get used to your presence after a while and allow you to get closer. The eyes of the male are grey/blue.

Orthetrum glaucum is a widespread species distributed throughout tropical and subtropical Asia and south and east to New Guinea. It is assessed by IUCN Red List as Least Concern.