Thalassobathia pelagica is a species of fish in the family Bythitidae (viviparous brotulas).

[7] Thalassobathia pelagica is bathypelagic,[8] living at depths of 500–1,000 m (1,600–3,300 ft) in the Atlantic Ocean.

[9] Two specimens have been collected between Iceland and Ireland, and one from the Gulf of Guinea.

A specimen from the Bering Sea has uncertain identification as this species.

[10] Thalassobathia pelagica lives in close association with the sea jelly Stygiomedusa gigantea.