Griseargiolestes fontanus is a species of Australian damselfly in the family Argiolestidae, commonly known as a springs flatwing. It is endemic to south-eastern Queensland and north-eastern New South Wales, where it inhabits streams near their springs.
Griseargiolestes fontanus is a medium-sized damselfly, black-green metallic in colour with pale markings; adults have only a slight pruinescence. Like other members of the family Argiolestidae, it rests with its wings outspread.
Griseargiolestes fontanus appears similar to Griseargiolestes albescens, though with less pruinescence.