A novel marine bacterium, strain LLJ827 T , was isolated from deep-sea waters from the Yonaguni Knoll IV hydrothermal vent in the Okinawa Trough. This Gram-stain-negative, strictly aerobic, rod-shaped organism exhibits a growth temperature range of 20–45 °C, with the optimal growth at 28 °C. The strain thrives in pH conditions ranging from 5.0 to 8.0 (optimal at pH 6.0) and can tolerate NaCl concentrations of 3–10%. The predominant respiratory of strain LLJ827 T was ubiquinone-10. The major fatty acids identified were summed feature 8 (comprising C 18:1 ω 7 c and/or C 18:1 ω 6 c ) and C 18:1 2-OH. The polar lipid profile included phosphatidylcholine (PC), phosphatidylglycerol (PG), diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), phosphatidylmonomethylethanolamine (PME), along with several unidentified phospholipids (PL), aminolipids (AL), glycolipids (GL) and lipids (L). The 16S rRNA gene sequence of strain LLJ827 T showed the closest similarity to Jiella avicenniae CBK1P-4 T (98.06%), followed by other Jiella species. Phylogenetic analysis based on 16S rRNA gene sequences also showed that strain LLJ827 T was clustered within the genus Jiella . The average nucleotide identity and DNA–DNA hybridization values of genomes of strain LLJ827 T and J. avicenniae CBK1P-4 T are 77.21 and 22.3%, respectively. The genomic G+C content of strain LLJ827 T is 64.0 mol%. Strain LLJ827 T has numbers of genes associated with carbohydrate metabolism, thiosulphate oxidation and [NiFe]-hydrogenases. Based on comprehensive polyphasic analysis, strain LLJ827 T is proposed as a novel species within the Jiella genus, named Jiella marina sp. nov., with the type strain designated as LLJ827 T (=MCCC 1K04957 T =KCTC 82884 T ).