Oenopota tenuicostata is a species of sea snail, a marine gastropod mollusk in the family Mangeliidae.
The length of the shell varies from 5 mm to 13 mm.
This species resembles Curtitoma decussata (Couthouy, 1839) but is smaller and has more numerous ribs.[1]
This marine species occurs off Greenland and Novaya Zemlya at depths between 200 m and 2702 m.