Pseudoplatystoma is a genus of several South American catfish species of the family Pimelodidae. The species are known by a number of different common names. They typically inhabit major rivers where they prefer the main channels and tend to stay at maximum depth, but some species can also be seen in lakes, flooded forests, and other freshwater habitats. They have robust bodies and are important food fish. Recently, their populations have been on the drastic decline due to a variety of factors, including overfishing and habitat destruction due to the construction of hydroelectric dams.

Pseudoplatystoma is a monophyletic genus of catfishes. P. fasciatum was the first species to be described, under the name Siluris fasciatus. In 1829, P. corruscans was described under the name Platystoma corruscans, and over a decade later, P. tigrinum was described as Platystoma tigrinum. In 1862, Pseudoplatystoma was described and these species transferred to it, with P. fasciatum as type species.

Unrecognized species of Pseudoplatystoma have been included under the names P. fasciatum and P. tigrinum for decades. This genus traditionally contained only three species until 2007; currently, eight species are in this genus. P. orinocoense, P. magdaleniatum, and P. reticulatum were formerly recognized as P. fasciatum, but are now recognized as distinct species. P. metaense is also now recognized as a distinct species from P. tigrinum.

Two clades are recognized within the genus. One is the P. fasciatum clade which includes P. fasciatum, P. orinocoense, P. magdaleniatum, P. reticulatum, and P. corruscans. Within this clade, P. fasciatum and P. punctifer are sister species, and P. orinocoense is sister to the clade formed by these two species. The other, the P. tigrinum clade, includes only P. tigrinum and P. metaense. They are differentiated by anatomical characters.

The intergeneric relationships of this genus are well established. It forms a monophyletic group with Sorubim, Sorubimichthys, Hemisorubim, and Zungaro. Of these genera, Hemisorubim is most closely related to Pseudoplatystoma.

In their native waters, these fish may be called surubí in Guaraní, especially in Paraguay, where still both Spanish and Guaraní are spoken. This name is also used in some Spanish-speaking countries and in Portuguese-speaking Brazil (surubi or surubim). In Peruvian Spanish, they are called doncella or zúngaro. P. corruscans may be called moleque or pintado. They often are referred to in the vernacular as bagre rayado/rajado or pintadillo/pintado (tiger catfish or tiger–shovelnose). P. corruscans, P. fasciatum, and P. tigrinum are also known as spotted sorubim, barred sorubim, and tiger sorubim, respectively. This genus is collectively referred to as the tiger shovelnose catfish in the aquarium hobby, as the species in this genus are relatively easy to confuse.

Pseudoplatystoma species are all large and boldly striped or spotted catfishes. They are familiar due to their distinctively marked color patterns. They are also recognized due to a depressed head, an occipital process extending backward to contact the predorsal plate, and a very long fontanel.

After gonadal maturation, females tend to grow faster than males. They have a large, depressed head with an expandable mouth. The eyes and teeth are small. They have dorsal and pectoral fin spines; P. fasciatum also has an additional, smaller, dorsal spinelet preceding the dorsal spine. They exhibit typical barbels of catfish, the maxillary barbels sometimes being quite long, especially in juveniles.