A Gram-negative, non-motile, rod-shaped, aerobic bacterial strain, designated S7-3-3T, was isolated from apple orchard soil in Gyeongsangnam-do province, South Korea, and was characterized taxonomically using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequence showed that strain S7-3-3T belonged to the family Cytophagaceae in the phylum Bacteroidetes was most closely related to Spirosoma rigui WPCB118T (94.3%), Spirosoma pulveris JSH5-14T (93.9%), and Spirosoma linguale DSM 74T (93.7%). The strain showed typical chemotaxonomic characteristics of the genus Spirosoma with a predominant respiratory quinone of menaquinone MK-7 and the major fatty acids of summed feature 3 (C16:1 ω7c/C16:1 ω6c; 43.9%) and C16:1 ω5c (25.6%). The G+C content of genomic DNA was 49.6 mol%. The polar lipid profile contained major amounts of phosphatidylethanolamine, an unidentified aminophospholipid, and an unidentified polar lipid. Phenotypic and chemotaxonomic data supported the affiliation of strain S7-3-3T with the genus Spirosoma. The results of physiological and biochemical tests showed the genotypic and phenotypic differentiation of the isolate from recognized Spirosoma species. On the basis of its phenotypic properties, genotypic distinctiveness, and chemotaxonomic features, strain S7-3-3T represents a novel species of the genus Spirosoma, for which the name Spirosoma agri sp. nov. is proposed. The type strain is S7-3-3T (= KCTC 52727T = JCM 32199T).