Okenia purpurata is a species of sea slug, specifically a dorid nudibranch, a marine gastropod mollusc in the family Goniodorididae.
This species was described from northern New South Wales, Australia. It is also known from Singapore.[1]
This Okenia has a narrow body and seven lateral papillae on each side and a single papilla in the middle of the back. The body is purple and the papillae are white. The rhinophores and gills are darker purple.
The diet of this species is the ctenostome bryozoan Amathia tortuosa. It shares this food preference with Okenia vena which is very similar in shape but completely different in coloration.