Sicyopus (Smilosicyopus) sasali n. sp., a carnivorous freshwater goby, is described from eight specimens (3 males, 5 females) collected in high gradient streams of Futuna Island, situated in the South Pacific, between Samoa and Fiji. S. Sasali differs from other species of the subgenus Smilosicyopus by the following combination of characters: more scales in lateral series (24-47), transverse back series (3-13) and transverse forward series (0-13); less scales in zigzag series (11-14); a greater length of anal fin; a shorter preanal length; and a shorter caudal peduncle.