Strain PSRT was isolated from seawater of the Pacific Ocean. Cells of the strain were Gram-stain-negative, strictly aerobic, rod-shaped and motile by gliding. Growth was observed at 4-40 °C (optimum 25-30 °C), at pH 6.0-9.5 (optimum pH 7.0-7.5) and with 0.5-8 % (w/v) NaCl (optimum 2-3 %). The major fatty acids were iso-C15 : 1 G (18.9 %), iso-C15 : 0 (26.3 %) and iso-C17 : 0 3-OH (17.9 %). The predominant isoprenoid quinone was MK-7, and the DNA G+C content was 49.3 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain PSRT was most closely related to Roseivirga spongicola UST030701-084T (96.9 % 16S rRNA gene sequence similarity), and they formed a distinct clade in neighbour-joining, maximum-likelihood and maximum-parsimony phylogenetic trees with significant bootstrap supports. Based on phenotypic, chemotaxonomic and phylogenetic characteristics, strain PSRT represents a novel species of the genus Roseivirga, for which the name Roseivirga marina sp. nov. is proposed. The type strain is PSRT ( = MCCC 1K00459T = KCTC 42444T).