A new species of sphaerodorid (Polychaeta: Sphaerodoridae), Sphaerodoropsisgarciaalvarezi sp. nov., is described from specimens collected on sandy bottoms off the Galician coast (Spain, north-east Atlantic). This species is characterized by having two pairs of digitiform lateral antennae, 13 dorsal macrotubercles per segment in mid-body setigers arranged in two transverse rows, five dorsal microtubercles per segment arranged in five longitudinal rows, six ventral papillae per segment arranged in six longitudinal rows, digitiform presetal lobes and ventral cirri, and composite setae with spinulation on blade and distal end of shaft. Complementary observations to original descriptions are also provided for closely related species Sphaerodoropsis bisphaeroserialis and Sphaerodoropsisarctowskyensis upon examination of type series.