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

[2] This species was described from the San Juan Islands, British Columbia, Canada, 48°34′07″N 123°00′21″W / 48.568625°N 123.005766°W / 48.568625; -123.005766.