A Gram-negative, non-motile, aerobic bacterium, designated strain KOPRI 20941(T), was isolated from a sample of marine sediment from Ny Alesund, Spitsbergen, Norway. A phylogenetic analysis based on 16S rRNA gene sequences revealed that the Arctic isolate nested within the genus Maribacter and showed the highest sequence similarity (98.1 %) with respect to Maribacter orientalis KMM 3947(T). Chemotaxonomic data (DNA G+C content of 36 mol%; MK-6 as the major respiratory quinone and iso-C(17 : 0) 3-OH, C(16 : 1)omega7c/iso-C(15 : 0) 2-OH and iso-C(15 : 0) as the major fatty acids) supported the affiliation of strain KOPRI 20941(T) to the genus Maribacter. The results of phylogenetic analyses, physiological and biochemical tests and a DNA-DNA reassociation test (<54 % relatedness) allowed genotypic and phenotypic differentiation of the strain from the recognized species of the genus Maribacter. Therefore strain KOPRI 20941(T) represents a novel species of the genus Maribacter, for which the name Maribacter arcticus sp. nov. is proposed. The type strain is KOPRI 20941(T) (=KCTC 22053(T)=JCM 14790(T)).