长颈鳗科为辐鳍鱼纲鳗鲡目的其中一个科。

长颈鳗科下分2个属，如下：

• 颈鳗属(Derichthys)
  • 短吻颈鳗(Derichthys serpentinus)
• 鸭颈鳗属(Nessorhamphus)
  • 丹氏鸭颈鳗(Nessorhamphus danae)
  • 鸭颈鳗(Nessorhamphus ingolfianus)

Longneck eels or neck eels are a family, Derichthyidae, of eels. They are pelagic fishes, found in the middle and depths of most oceans. The name comes from Greek deres meaning "neck" and ichthys meaning "fish".

They are distinguished by the presence of a series stripes on the head that form part of the sensory system, but otherwise the two genera of the family are quite different in appearance. Derichthys has a narrow neck and large eyes, while Nessorhamphus' has a long, flattened, snout. They grow to about 60 cm (24 in) in length.