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

It is found on the Atlantic coast from Portugal to Pembrokeshire in South Wales.

[3] This goniodorid nudibranch is translucent white in colour, with yellow-orange markings.

The rhinophores, gills and processes are tipped with yellow pigment which becomes orange at the extremities.

[3] Trapania tartanella feeds on Entoprocta which often grow on sponges.