Gymnogeophagus is a genus of cichlid fishes from South America, where they are known from various river basins (notably Rio de la Plata and Lagoa dos Patos–Mirim) in southern Brazil, Paraguay, Uruguay and northern Argentina. They are part of a group popularly known as eartheaters.

Species

There are currently 18 recognized extant species in this genus: An extinct species Gymnogeophagus eocenicus lived during the Early Eocene of Argentina, around, representing one of the oldest known cichlids.