Octopus vitiensis, or the bighead octopus, is a species of octopus provisionally placed in the genus Octopus. It was described by William Evans Hoyle in 1885<ref>{ { Cite journal |last=Hoyle |first=William E. |date=1885 |title=XIX.—Diagnoses of new species of Cephalopoda collected during the cruise of H.M.S. 'Challenger.'''—Part I. The Octopoda |url=http://dx.doi.org/10.1080/00222938509459320 |journal=Annals and Magazine of Natural History |volume=15 |issue=87 |pages=222–236 |doi=10.1080/00222938509459320 |issn=0374-5481}}</ref> based on a specimen found in reefs in Kandavu, Fiji during a voyage of HMS Challenger.
Description O. vitiensis is maroon to dark purple-black in color. It has large eyes, a broad head, and arms of moderate length. The species is described as robust and muscular with scattered warts on the skin. O. vitiensis is small, and has a mantle length of up to 60 millimeters and a total length of up to 250 millimeters.
Distribution O. vitiensis is tropical, found in Fiji, Tonga, and Papua New Guinea; and benthic, found at depths of zero to 20 meters.
Life cycle O. vitiensis'' lays eggs two millimeters in length.