A Gram-stain-positive and motile bacterial strain, designated IB182363T, was isolated from surface seawater of the South China Sea. Cells grew at pH 5.0-9.5 (optimum, pH 7.0-8.0), 20-40 °C (optimum, 30 °C) and with 1-8 % (w/v) NaCl (optimum, 2-4 %). On the basis of 16S rRNA gene sequence analysis, strain IB182363T was affiliated to the genus Paenibacillus and the closest phylogenetically related species was Paenibacillus ginsengarvi DSM18677T with 96.9 % sequence similarity. The values of whole genome average nucleotide identity analysis and digital DNA-DNA hybridization between the isolate and the closely related type strains were less than 86.3 and 25.6 %, respectively. Chemotaxonomic analysis revealed that strain IB182363T possessed meso-diaminopimelic acid in the cell-wall peptidoglycan and contained menaquinone MK-7 as the predominant isoprenoid quinone. The major cellular fatty acids were anteiso-C15 : 0, C16 : 0 and iso-C16 : 0. The polar lipids comprised phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, one unidentified glycolipid, two unidentified aminolipids, two unidentified phospholipids and four unidentified aminophospholipids. The genomic DNA G+C content was 54.5 mol%. On the basis of the above results, strain IB182363T represents a novel species of the genus Paenibacillus, for which we propose the name Paenibacillus oceani sp. nov. with the type strain IB182363T (=MCCC 1K04630T=JCM 34214T).