Phyllogobius platycephalops, the Slender spongegoby, is a species of goby native to the western Indian Ocean and the western Pacific Ocean where it occurs on reefs at depths of from 2mto18mm (07feetto59feetm). This species is a commensal on sponges of the genus Phyllospongia. This species grows to a length of 5cm (02inches) SL. This species is the only known member of its genus.