A Gram-stain-negative, non-motile, non-spore-forming, rod-shaped, aerobic bacterium, designated 15J9-8 T , was isolated from soil on Jeju Island, Republic of Korea. The isolate was able to grow between 10 and 30°C, pH 6.5–8.5, and in presence of 0–1% (w/v) NaCl. The results of comparative 16S rRNA gene sequence analysis indicated that strain 15J9-8 T represented a member of the family Cytophagaceae , phylum Bacteroidetes , and was most closely related to Spirosoma aerophilum 5516J-17 T (96.1% similarity), Spirosoma pulveris JSH5-14 T (95.6%), and Spirosoma linguale DSM 74 T (95.2%). The G + C content of the genomic DNA of the isolate was 47.0 mol%. Strain 15J9-8 T contained summed feature 3 (C 16:1 ω 7 c /C 16:1 ω 6 c ), C 16:1 ω 5 c , and iso-C 15:0 as the major fatty acids, phosphatidylethanolamine and an unidentified aminophospholipid as the main polar lipids, and menaquinone MK-7 as the predominant respiratory quinone. On the basis of its phenotypic and genotypic properties, and phylogenetic distinctiveness, strain 15J9-8 T should be classified as a representative of a novel species of the genus Spirosoma , for which the name Spirosoma migulaei sp. nov. is proposed. The type strain is 15J9-8 T (=KCTC 52028 T =JCM 31996 T ).