A Gram-stain-negative, aerobic, non-motile, white-pigmented, short rod-shaped, and alginate-degrading bacterium, designated B1Z28T, was isolated from the gut of the abalone Haliotis rubra obtained at Weihai, China. Strain B1Z28T was found to grow at 4-35 °C, pH 6.5-9.0, and in the presence of 0.5-8.0% (w/v) NaCl. Cells were positive for oxidase and catalase activity. The 16S rRNA-based phylogenetic analysis revealed that the nearest phylogenetic neighbors of strain B1Z28T were Tritonibacter scottomollicae MCCC 1A06440T (98.1%), Ruegeria faecimaris KCTC 23044T (98.0%), and Ruegeria meonggei KCTC 32450T (97.8%). Based on phylogenomic analysis, the average nucleotide identity (ANI) values between strain B1Z28T and the neighbor strains were 71.6, 77.2, and 78.1%, respectively; the digital DNA-DNA hybridization (dDDH) values based on the draft genomes between strain B1Z28T and its closest neighbors were 20.5, 20.8, and 21.6%, respectively. Ubiquinone-10 (Q-10) was detected as the predominant respiratory quinone. The dominant cellular fatty acids were Summed feature 8 (contained C18:1 ω7c and/or C18:1 ω6c). The polar lipids included phosphatidylethanolamine (PE), diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), phospholipid (PL), aminolipid (AL), and three unidentified lipids. Based on the phylogenetic and phenotypic characteristics, strain B1Z28T is considered to represent a novel species of the genus Ruegeria, for which the name Ruegeria haliotis sp. nov. is proposed. The type strain is B1Z28T (= KCTC 72686T = MCCC 1H00393T).