A Gram-stain-negative, strictly aerobic and moderately halophilic bacterium, designated strain MA-7-27T, was isolated from a marine red alga, Porphyridium marinum, in the Republic of Korea. The cells of strain MA-7-27T were non-motile rods showing oxidase- and catalase-positive activities. Growth of strain MA-7-27T was observed at 15-45 °C (optimum, 30 °C), pH 5.0-9.0 (pH 7.0) and in the presence of 0.0-5.0 % (w/v) NaCl (2.0 %). Strain MA-7-27T contained C10 : 0, summed feature 1 (comprising iso-C15 : 1 h and/or C13 : 1 3-OH) and summed feature 8 (comprising C18 : 1 ω7c and/or C18 : 1 ω6c) as the major fatty acids. The only isoprenoid quinone detected was ubiquinone-10. The major polar lipids of strain MA-7-27T were phosphatidylglycerol, two unidentified phospholipids and two unidentified aminolipids. The G+C content of the genomic DNA was approximately 63.6 mol%. Strain MA-7-27T was most closely related to the type strains of Boseongicola aestuarii BS-W15T and Nioella nitratireducens SSW136T with 96.98 % and 96.12 % 16S rRNA gene sequence similarities, respectively, but phylogenetic analyses showed that strain MA-7-27T formed a clearly distinct phylogenic lineage from the closely related strains. The phenotypic, chemotaxonomic and molecular properties support that strain MA-7-27T represents a novel genus of the family Rhodobacteraceae, for which the name Rhodophyticola porphyridii gen. nov., sp. nov. is proposed. The type strain is MA-7-27T (=KACC 18805T=JCM 31537T).