Turbinaria foliosa sp. nov. is described on the basis of several collections made from Dhofar, Sultanate of Oman. The new species is known only from southern Oman, a region of the northern Arabian Sea that is strongly impacted by the upwelling from the summer-time monsoon. It is distinguished from other species of the genus by the shape of the leaves and by their loose, non-congested arrangement. Air vesicles, embedded in the leaves, may be present, but more often are absent. A census of the currently recognized species in the genus Turbinaria is provided. Reference is made to Sargassum turbinarioides and Sargassum turbinatifolium. These species possess discrete blades and spherical vesicles and thus conform to Sargassum.