Weevers (or weeverfish) are nine extant species of fishes of family Trachinidae, order Trachiniformes, part of the Percomorpha clade. They are long (up to 37 cm), mainly brown in color, and have venomous spines on their first dorsal fin and gills. During the day, weevers bury themselves in sand, just showing their eyes, and snatch prey as it comes past, which consists of shrimp and small fish.

Weevers are unusual in not having swim bladders, as do most bony fish, and as a result, sink as soon as they stop actively swimming. With the exception of T. cornutus from the southeast Pacific, all species in this family are restricted to the eastern Atlantic (including the Mediterranean). A tenth, extinct species, Callipterus speciosus, is known from the Monte Bolca lagerstätte of the Lutetian epoch.

Weevers are sometimes used as an ingredient in the recipe for bouillabaisse.

Weevers are sometimes erroneously called 'weaver fish', although the word is unrelated. In fact, the word 'weever' is believed to derive from the Old French word wivre, meaning serpent or dragon, from the Latin vipera. It is sometimes also known as the viperfish, although it is not related to the viperfish proper (i.e., the stomiids of the genus Chauliodus).

In Australia, sand perches of the family Mugilidae are also known as weevers.

In Portugal, the weever is known as peixe-aranha, which translates to 'spider-fish', and in Catalan as aranya, which is identical to the word for 'spider'.