Cutthroat eels are a family, Synaphobranchidae, of eels, the only members of the suborder Synaphobranchoidei. They are found worldwide in temperate and tropical seas.

Cutthroat eels range from 23 to 160 cm in length. They are bottom-dwelling fish, found in deep waters down to about 3700 m. They are distinguished by the presence of telescopic eyes in the larvae. In some classifications (for example, ITIS),