Jorunna is a genus of sea slugs, dorid nudibranchs, shell-less marine gastropod molluscs in the family Discodorididae.

[2] The name Jorunna comes from the latinization of the name of the character Jorunn from the Laxdæla saga.

[3] Jorunna species are usually camouflaged to match the sponges they feed on, which in many cases belong to the family Chalinidae.

It is likely that many undescribed species exist.

[4] There are more than 20 species in genus Jorunna.