The Family Percichthyidae are known as the Temperate perches. They belong to the Order Perciformes or perch-like fishes.

The Temperate Perches are closely related to the Temperate Basses of the Family Moronidae, and older literature treats the latter as a belonging to the Family Perchichthyidae.

Around 22 species of percichthyids are now recognised, grouped in around 11 genera. Most but not all are freshwater fishes. They are mainly found in Australasia and South America, though some (notably genus Siniperca, which has the largest number of species) are native to Asia, and some of the marine species are found as far north in the Pacific as California. Australia has the greatest number of species, where they are represented by Australian freshwater cods such as Murray cod, eastern freshwater cod, trout cod and sleepy cod plus other closely allied species.

A number of species are or have been important food species; some of these (e.g. the Murray Cod, Maccullochella peelii) have become endangered through overfishing, while others (e.g. the Chinese Perch, Siniperca chuatsi), are now farmed to some extent. Some smaller species (e.g. Balston's pygmy perch, Nannatherina balstoni) are popular in aquaria.