A Gram-stain-negative, strictly aerobic, short-rod-shaped, and non-motile bacterial strain designated HSLHS9T was isolated from surface seawater collected from the South China Sea. Strain HSLHS9T could grow at 15–41°C (optimum 28°C), at pH 5.0–9.0 (optimum 6.0–7.0), and in 0–7% (w/v) NaCl (optimum 2–3%). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain HSLHS9T shared high identities with the closely related Parahaliea aestuarii S2-26T (98.6%) and Parahaliea mediterranea 7SM29T (97.8%) and formed a distinct lineage within the genus Parahaliea. Wholegenome sequencing of strain HSLHS9T revealed the size of 4.8 Mbp and DNA G + C content of 61.8 mol%. Strain HSLHS9T shared the digital DNA-DNA hybridization values of 22.4% and 23.0%, and the average nucleotide identities of 79.7% and 79.9%, respectively, with the two type strains above. The predominant cellular fatty acids of the strain were summed feature 8 (C18:1 ω6c and/or C18:1 ω7c), summed feature 3 (C16:1 ω7c and/or C16:1 ω6c), C17:1 ω8c, and C16:0. The sole isoprenoid quinone was identified as Q-8. The polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, aminolipid, and two glycolipids. Based on taxonomic data obtained in this study, it is suggested that strain HSLHS9T represents a novel species of the genus Parahaliea, for which the name Parahaliea maris sp. nov. is proposed. The type strain is HSLHS9T (= MCCC 1A06717T = KCTC 52307T). An emended description of the genus Parahaliea is also provided.