Trapania orteai is a species of sea slug, a dorid nudibranch, a marine gastropod mollusc in the family Goniodorididae.

[3] The body of this goniodorid nudibranch is translucent white in colour, with elongate orange spots.

The rhinophores and gills are yellow-brown and there is a patch of orange grading to yellow on the tail.

The oral tentacles and lateral papillae are yellow with white bases and a hint of orange at the base of the yellow.

[4] Trapania orteai probably feeds on Entoprocta which often grow on sponges.