| Hysteronotus | |
|---|---|
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Division: | Teleostei |
| Order: | Characiformes |
| Family: | Stevardiidae |
| Subfamily: | Stevardiinae |
| Genus: | Hysteronotus C. H. Eigenmann, 1911 |
| Species: | H. megalostomus |
| Binomial name | |
| Hysteronotus megalostomus C. H. Eigenmann, 1911 | |

Hysteronotus is a monospecific genus of freshwater ray-finned fish belonging to the family Stevardiidae. The only species in the genus is Hysteronotus megalostomus, a characin, which is endemic to Brazil in the drainage system of the São Francisco River.