Leiocassis is a genus of bagrid catfishes found mostly in Southeast Asia with some species occurring in China. This genus has a confused taxonomy and there is uncertainty surrounding the number of valid species. Certain East Asian bagrids formerly placed in this genus have been moved to Pseudobagrus. In 2006, Heok Hee Ng considered the genus Leiocassis to be restricted to Sundaic Southeast Asia and Borneo and only a handful of species as valid (L. aculeatus, L. collinus, L. hosii, L. micropogon, L. poecilopterus, and L. tenebricus).