Cumanotus beaumonti is a species of sea slug, an aeolid nudibranch, a marine gastropod mollusc in the family Cumanotidae.

[2] This species was described from Jennycliff Bay, Plymouth Sound, Devon, England, 50°20′58″N 4°07′36″W / 50.34931°N 4.12678°W / 50.34931; -4.12678.

It has been reported from the Irish Sea (including the Douglas, Isle of Man Marine Nature Reserve[3]) Scotland and Norway.

[4]