Trinchesia foliata is a species of sea slug, an aeolid nudibranch, a marine gastropod mollusk in the family Trinchesiidae.
This species was described from Orkney, Scotland. It has been reported from the NE Atlantic, from the Faeroes and Norway south to Portugal, and in the Mediterranean Sea.
The typical adult size of this species is 8âÂÂ11 mm.
Trinchesia foliata feeds on hydroids. It has been reported from a number of hydroids including Dynamena pumila, Sertularella gayi, Sertularella polyzonias and Abietinaria abietina family Sertulariidae.