Anglerfishes are members of the teleost order Lophiiformes. They are bony fishes named for their characteristic mode of predation, in which a fleshy growth from the fish's head (the esca or illicium) acts as a lure.

Anglerfish are also notable for extreme sexual dimorphism seen in the suborder Ceratioidei, and sexual parasitism of male anglerfish. In these species, males may be hundreds to thousands of times smaller than females.

Anglerfish occur worldwide. Some are pelagic while others are benthic; some live in the deep sea (e.g., Ceratiidae) while others on the continental shelf (e.g., the frogfishes Antennariidae and the monkfish/goosefish Lophiidae). Pelagic forms are most laterally compressed whereas the benthic forms are often extremely dorsoventrally compressed (depressed) often with large upward pointing mouths.