Jorunna tomentosa is a species of sea slug, a dorid nudibranch, a shell-less marine gastropod mollusc in the family Discodorididae.

[2] This species occurs in European waters from Norway to Portugal and in the Mediterranean Sea.

It has also been reported from South Africa and Tristan da Cunha.

[3][4] Jorunna tomentosa feeds on the sponges Haliclona cinerea and Haliclona oculata.

[5]