A Gram-staining-positive, strictly aerobic, non-spore-forming, rod-shaped bacterial strain, CAU 9163(T), was isolated from marine sediment collected in the Republic of Korea and its taxonomic position was investigated using a polyphasic approach. The novel strain grew optimally at 30 °C and pH 8.0. In phylogenetic analysis based on 16S rRNA gene sequences, strain CAU 9163(T) formed a hitherto unknown lineage within the order Bacillales, which contains the genera Planomicrobium, Planococcus, Sporosarcina, Rummeliibacillus, Viridibacillus, Lysinibacillus and Bacillus. The levels of 16S rRNA gene sequence similarity between the novel strain and any established bacterial species were all <95.7%. The major isoprenoid quinines of strain CAU 9163(T) were MK-8 (65.2%) and MK-7 (22.8%) and the predominant fatty acid was anteiso-C(15:0). The peptidoglycan was of the A4α type and based on L-Lys-D-Asp. The major whole-cell sugars were ribose and glucose. The polar lipid profile mainly consisted of phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, an unidentified glycolipid and an unidentified polar lipid. The genomic DNA G+C content of the novel strain was 44.3 mol%. These data were sufficient to differentiate the novel strain from established genera in the phylum Firmicutes. Based on the phenotypic, chemotaxonomic and genotypic evidence, strain CAU 9163(T) represents a novel species in a new genus for which the name Chungangia koreensis gen. nov., sp. nov. is proposed. The type strain of Chungangia koreensis is 9163(T) ( = KCTC 13729(T) = CCUG 59778(T)).