巨口鱼目是辐鳍鱼纲的其中一目，下分5科：

• 双光鱼科(Diplphidae)FishBase中本科已并入钻光鱼科
• 钻光鱼科(Gonostomatidae)
• 褶胸鱼科(Sternoptychidae)
• 光器鱼科(Phosichthyidae)
• 巨口鱼科(Stomiidae)

Stomiiformes is an order of deep-sea ray-finned fishes of very diverse morphology. It includes, for example, dragonfishes, lightfishes, loosejaws, marine hatchetfishes and viperfishes. The order contains 4 families (5 according to some authors) with more than 50 genera and at least 410 species. As usual for deep-sea fishes, there are few common names for species of the order, but the Stomiiformes as a whole are often called dragonfishes and allies or simply stomiiforms.