A Gram-negative, strictly aerobic, beige-pigmented, non-motile, rod-shaped strain designated H-MN17(T) was isolated from seawater in Japan. Phylogenetic analyses based on the 16S rRNA gene sequence revealed that the novel isolate was affiliated with the family Flavobacteriaceae within the phylum Bacteroidetes and that it showed highest sequence similarity (97.5 %) to Wenyingzhuangia marina D1(T). The hybridization values for DNA-DNA relatedness between the strains of H-MN17(T) and W. marina D1(T) were lower than 70 %, which is accepted as the phylogenetic definition of a novel species. The DNA G+C content of strain H-MN17(T) was 31.8 mol%; MK-6 was the major menaquinone; and anteiso-C15:0, anteiso-C17:0 and anteiso-C19:0 were identified as the major (>10 %) cellular fatty acids. A complex polar lipid profile was present consisting of phosphatidylethanolamine, three unidentified lipids, three unidentified glycolipids and three unidentified aminolipids. From the distinct phylogenetic position and combination of genotypic and phenotypic characteristics, the strain is considered to represent a novel species of the genus Wenyingzhuangia for which the name Wenyingzhuangia heitensis sp. nov. is proposed. The type strain of W. heitensis sp. nov. is H-MN17(T) (=KCTC 42245(T) = NBRC 110601(T)).