Helichthys is an extinct genus of prehistoric bony fish that lived during the Early Triassic epoch in what is now South Africa.

Although several species of Helichthys have been erected (H. elegans, H. stegopyge, H. obesus, H. ctenipteryx, H. grandipennis), they were later all synonymized with the type species, H. browni. Fossils were recovered from the Lower Cynognathus Assemblage Zone of Bekker's Kraal.