Duopalatinus is a small genus of long-whiskered catfishes native to South America.

There are currently two recognized species in this genus:[1] Duopalatinus is classified under the "Calophysus-Pimelodus clade".

Within this clade, it is considered a part of the "Pimelodus-group" of Pimelodids, which also includes Pimelodus, Exallodontus, Cheirocerus, Iheringichthys, Bergiaria, Bagropsis, Parapimelodus, Platysilurus, Platystomatichthys, and Propimelodus.

D. emarginatus inhabits the São Francisco River basin.

[3] D. peruanus is found in the Amazon and Orinoco River basins.