Gadiformes, also called the Anacanthini, are an order of ray-finned fish that include the cod, hakes, pollock, haddock, burbot, rocklings and moras, many of which are food fish of major commercial value. They are mostly marine fish found throughout the world and the vast majority are found in temperate or colder regions while a few species may enter brackish estuaries. Pacific tomcods, one of the two species that makes up the genus Microgadus, are able to enter freshwater, but there is no evidence that they breed there. Some populations of landlocked Atlantic tomcod on the other hand, complete their entire life cycle in freshwater. Yet only one species, the burbot, is a true freshwater fish.

Cod is the common name for the demersal fish genus Gadus, belonging to the family Gadidae. Cod is also used as part of the common name for a number of other fish species, and one species that belongs to genus Gadus is commonly not called cod.