Opisthoteuthis chathamensis, commonly known as the roughy umbrella octopus, is a species of cirrate octopus found in demersal habitats surrounding the Chatham Rise in New Zealand and Macquarie Island (Australian Antarctic Territories).
Opisthoteuthis chathamensis reaches a maximum length of TL, and a mantle length of . They are described as having subequal arms with around 41-45 suckers in males and 45-55 suckers in females. Their oral surface and the webbing between their tentacles is maroon and the suckers are a pale cream.
The type locality of O. chathamensis is near the Chatham Islands at <small>44ð44'S, 77ð15'W</small>, , and was found more broadly around the Chatham Rise, off New Zealand, over a depth range of , living on soft sediments..
The species has also more recently been collected from Macquarie Island, to the South West of New Zealand .
Opisthoteuthis chathamensis is listed as Critically Endangered by the IUCN due to a 70% decrease in population size in recent years, and has not been seen since 1999, when it was a common bycatch species. In addition, their longevity, low fecundity and slow growth (especially embryonic development which lasts 1.4-2.6 years among other species in the genus) has made them particularly susceptible to population declines and slow recoveries.