With maximum size of 30 mm, wingspan of 35 mm, it is a small species, all sky blue and black, with no black marking on abdominal S8, which is all blue. For male, the face is light blue and black. Labrum light blue with fina black base. Anteclypeus dirty light blue. Postclypeus black. Fons and genae light blue. Head above with balck transverse band. A blue line runs across occiput but usually does not quite reach eyes. Sometimes this line is broken, forming postocular spots. Eyes light blue with black cap. Cap coincides with black head band. Prothorax black with fine, broken light blue margins. Synthorax black and light blue stripes. Sometimes the blue is very light and brownish, and even occasionally completely brown. Wings clear, pterostigmas dark grey, almost black, with fine pale margins. Abdomen light blue with a black dorsal line of varying widths, that ends in a taper at end of S7. S8-S9 above all blue. S10 blue with fine black stripe above. Superior appendages mostly blue. Female with similar markings as male but light brown instead of blue.

The species is one of the commonest species in southern Africa, becoming progressively scarcer in the north and especially westwards in Africa. Most recordings of the Swamp Bluet (Africallagma glaucum) have been in locations of 1,200m above sea level at perennial or temporary waters with submerged aquatic vegetation. This is a widespread species with no known major widespread threats. It is assessed by IUCN Red List as Least Concern as it is unlikely to be declining fast enough to qualify for listing in a threatened category.