Hemigrammus erythrozonus, commonly known as the glowlight tetra, is a small tropical fish from the Essequibo River, Guyana, South America. It is silver in colour and a bright iridescent orange to red stripe extends from the snout to the base of its tail, the front of the dorsal fin being the same color as the stripe. Other fins are silver to transparent. The glowlight tetra is a peaceful, shoaling fish. It is larger than the neon tetra, and its peaceful disposition makes it an ideal, and popular, community tank fish. It should be kept with similar sized, non-aggressive species. Hemigrammus gracilis is a senior synonym. The red-line rasbora (Rasbora pauciperforata) of Malaysia and Indonesia has markings and coloring very similar to H. erythrozonus, but is a member of family Cyprinidae, not a close relative.

H. erythrozonus is a medium-sized tetra growing to 4 to 5 cm (1.6 to 2.0 in), notably larger than both neon and cardinal tetras. It has a life span of two to four years when kept in good conditions.

In the wild, the fish eats aquatic insect larvae.