A Gram-negative, orange-pigmented, rod-shaped bacterium, designated strain $CP32^T$ was isolated from a brown alga Carpopeltis affinis collected on the coast of Jeju Island, Republic of Korea. The isolate grew at $10-37^{circ}C$ (optimum $25^{circ}C$) and at pH 6.5-9.5 (optimum pH 7.0). The 16S rRNA gene sequence of the isolate showed much similarity with the type strains of recognized species of the genus Winogradskyella (94.0-96.6%). The most closely related species were Winogradskyella echinorum KMM $6211^T$, Winogradskyella ulvae KMM $6390^T$, Winogradskyella thalassocola KMM $3907^T$, Winogradskyella poriferorum UST030701-$295^T$, and Winogradskyella eximia KMM $3944^T$. The major respiratory quinone was menaquinone-6 (MK-6) and the predominant cellular fatty acids were iso-$C_{15:1}$ G (24.8%), iso-$C_{15:0}$(23.4%), and iso-$C_{17:0}$ 3-OH (11.6 %). The DNA G+C content was 33.3 mol%. The polar lipid profile was composed of phosphatidylethanolamine, two aminolipids, and five unknown lipids. On the basis of phenotypic features, and the result of 16S rRNA gene sequence analysis, strain $CP32^T$ (=KCTC $23835^T$ =JCM $18454^T$) represents a novel species of the genus Winogradskyella, for which the name Winogradskyella jejuensis sp. nov. is proposed.