Alepocephaliformes is an order of marine deep-sea teleost fishes. It was previously classified as the suborder Alepocephaloidei of the order Argentiniformes.
As an adaptation to a life in the deep-sea, they have no swim bladder, and the ossification of the skeleton is reduced. The largest known member is Narcetes shonanmaruae, the largest deep-sea-endemic bony fish.