A novel bacterial strain, designated NA-09(T), was isolated from a freshwater sample collected from the Cheonho reservoir, Republic of Korea. Colonies were creamy-white pigmented, translucent, and circular with convex shape. The isolate was Gram-staining negative, strictly aerobic, motile, and rod-shaped. The 16S rRNA gene sequence analysis revealed that strain NA-09(T) belonged to the genus Arenimonas and showed the highest sequence similarities with Arenimonas malthae CC-JY-1(T) (95.4%), A. oryziterrae YC6267(T) (94.9%), A. composti P2-12-1(T) (94.8%), and A. donghaensis H03-R19(T) (94.1%). The major fatty acids were iso-C(16:0) (20.8%), iso-C(15:0) (16.9%), summed feature 1 (13.2%), and iso-C(16:1) ω7c alcohol (10.2%). The major isoprenoid quinone of the isolate was ubiquionone-8. On the basis of the data from the polyphasic characterization, the strain NA-09(T) represents a novel species, for which the name Arenimonas aquatica [corrected] sp. nov. is proposed (type strain NA-09(T) =KACC 14663(T) =NBRC 106550(T)).