The Hypoptopomatinae are a subfamily of catfishes of the family Loricariidae, composed of 17 genera and approximately 80 species. This subfamily represents about one-tenth of all loricariid species.

Loricariidae is the largest family of catfish, with over 90 genera and just over 680 species. Loricariids originate from freshwater habitats of Costa Rica, Panama, and tropical and subtropical South America. Fossils indicate that they also inhabited Africa during the Cretaceous. These fish are noted for the bony plates covering their bodies and their suckermouths. Several genera are sold as "plecos", notably the suckermouth catfish, Hypostomus plecostomus, and are popular as aquarium fish.