Among the many octopods collected during recent Antarctic trawling surveys were 93 specimens of an undescribed octopod with biserial suckers. Although most similar in appearance to the sub-Antarctic Benthoctopus levis (Hoyle 1885), these octopods differed in several morphological characters, including arm length, web depth, and details of the hectocotylus. Furthermore, molecular evidence supports the separation of the present material from known species. We therefore describe a new species named Benthoctopus rigbyae. These octopods attain mantle lengths of at least 105 mm (400 mm total length), and they are common at depths of 250-600 m throughout the South Shetland Island chain off the Antarctic Peninsula. We present some information on the biology of this species.