Bathysoma is an extinct genus of marine lampriform ray-finned fish from the early-mid Paleocene.

Its fossils are common in exposures of the Danian København Limestone Formation at Limhamns kalkbrott, one of the largest quarries in northern Europe.

A single specimen is also known from an erratic boulder from the Selandian Lellinge Greensand Formation of southern Sweden.

[5] Eventually, anatomical similarities with the turkmenids were noted, and B. lutkeni is now regarded as an extremely basal lamprid.

[4][6] This article about a prehistoric ray-finned fish is a stub.