Opsarius pulchellus, is a species of fish in the family Danionidae, with the largest individual recorded being 11 cm long.

[2] "Pulchellus" is a Latin diminutive meaning "beautiful".

They are mainly found in fast flowing rivers or clear hill streams.

O. pulchellus are rarely found in markets, but are exploited by subsistence fisheries and occasionally for the aquarium trade.

Habitat degradation through sedimentation increase (e.g. by large-scale damming) may become problematic in the future, especially along the Mekong and Chao Phraya.