A new species of Orbiniidae, Scoloplos juanfernandezensis n. sp. from the Robinson Crusoe Island (33°37’S, 78°51’W), Juan Fernández Archipelago, Chile, is described. The samples were collected by means of SCUBA from depths between 4 and 10 m, between the years 2008 and 2012. This is the first record of the family Orbiniidae for the Juan Fernández Archipelago. The new species is principally characterized by the dichotomously branched branchiae in the mid-posterior chaetigers with 2 to 4 terminal filaments, thoracic neuropodial hooks hooded, neuropodial acicula embedded with straight distal end, emergence of the first branchiae between chaetigers 20-28, but starting not always occurs on both sides of the segment at a time, the absence of subpodials papillae and the morphology of the parapodia. Scoloplos juanfernandezensis most closely resembles Scoloplos cylindrifer Ehlers, 1905, from New Zealand and Australia and Leodamas latum (Chamberlin, 1919) from Pacific side of Panamá.
Keywords: benthic polychaetes, annelids, Orbiniids, biodiversity, Southeastern Pacific Ocean.