A Gram-negative, aerobic, motile and rod-shaped bacterium, designated strain T7-07(T), was isolated from compost in Daejeon, Korea. Phylogenetic analysis based on 16S rRNA gene sequencing showed that strain T7-07(T) had 99.0% gene sequence similarity with Arenimonas malthae KACC 14618(T) and 94.7-95.9% with other recognized species of the genus Arenimonas. Cells formed creamy white to yellowish colonies on R2A agar and contained Q-8 as the predominant ubiquinone, C(15:0) iso, C(16:0) iso, C(17:1) iso ω9c and C(11:0) iso 3-OH as the major fatty acids, and diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylmethylethanolamine and an unknown aminolipid as the major polar lipids. The DNA G+C content of strain T7-07(T) was 68.3 mol%. DNA-DNA reassociation experiments between T7-07(T) and Arenimonas malthae KACC 14618(T) resulted in a mean relatedness value of 22.2%. Combined genotypic and phenotypic data supported the conclusion that the strain T7-07(T) represents a novel species, for which the name Arenimonas daejeonensis sp. nov. is proposed. The type strain is T7-07(T) (=KCTC 12667(T)=DSM 18060(T)).