Pygopterus is an extinct genus of prehistoric bony fish that lived during the Wuchiapingian to Olenekian ages (late Permian to Early Triassic epochs) in what is now England, Germany (Baden-Württemberg, Saxony-Anhalt), Greenland and Svalbard (Spitsbergen). It is one of the few genera of ray-finned fish known to cross the Permian-Triassic boundary.
Fossils have been found in the Marl Slate Formation, Kupferschiefer (Werra Formation), Ravnefjeld Formation, Vikinghøgda Formation and Buntsandstein. A report about the discovery of this fish in Westphalian deposits of Belgium was likely caused by the presence of Nematoptychius which was referred to as Pygopterus in late 19th century.