Doris affinis Gmelin, 1791 (original combination) Flabellina affinis is a species of sea slug within the clade of aeolid nudibranch; a marine gastropod mollusk in the family Flabellinidae.

[2] This species is found in depths to 50 m in European waters in the Atlantic Ocean from Portugal to Ghana and the Canaries and is widespread in the Mediterranean Sea.

[3] The species can grow to a length of 50 mm.

It feeds primarily on species of Eudendrium, a very common hydroid genus in the Mediterranean Sea.

Flabellina affinis is often confused with Paraflabellina ischitana, but can be distinguished as follows: