A Gram-stain-negative, strictly aerobic and moderate halotolerant bacterial strain, designated S2-26T, was isolated from sediment of the Asan Bay estuary in South Korea. Cells were motile rods with two polar flagella showing oxidase and catalase activities. Growth of S2-26T was observed at 15-45 °C (optimum, 25 °C) and pH 5.5-10.0 (optimum, pH 7.0-8.5) and in the presence of 0-8.0 % (w/v) NaCl (optimum, 2.0 %). S2-26T contained C17 : 1ω8c, summed feature 8 (comprising C18 : 1ω7c and/or C18 : 1ω6c), summed feature 3 (comprising C16:1ω7c/C16:1ω6c) and C17 : 0 as the major fatty acids and ubiquinone-8 as the sole isoprenoid quinone. The polar lipids of S2-26T consisted of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, an unknown phospholipid, an unknown aminolipid, an unknown glycolipid and an unknown lipid. The G+C content of the genomic DNA was 62.2 mol%. The results of phylogenetic analysis based on 16S rRNA gene sequences indicated that S2-26T formed a tight phylogenetic lineage with Parahaliea mediterranea 7SM29T with a 100 % bootstrap value. S2-26T was most closely related to the type strain of Parahaliea mediterranea, with a 97.8 % 16S rRNA gene sequence similarity, and its DNA-DNA relatedness level was 45.2±2.2 %. On the basis of phenotypic, chemotaxonomic and molecular properties, it is clear that S2-26T represents a novel species of the genus Parahaliea, for which the name Parahaliea aestuarii sp. nov. is proposed. The type strain is S2-26T (=KACC 18801T=JCM 31547T).