A Gram-stain-negative, aerobic, non-motile and short rod-shaped bacterium, designated strain SCSIO 64248T, was isolated from the stony coral Fungia sp. collected from South China Sea. Phylogenetic analysis indicated that strain SCSIO 64248T belonged to the family Geminicoccaceae and showed the highest 16S rRNA gene similarities with the types of Marinimicrococcus flavescens (90.5%), Arboricoccus pini (90.2%) and Benzoalithermus flavus (89.8%). The whole genome of strain SCSIO 64248T was 4.9 Mbp with a 68.8mol% G+C content. It shared average amino acid identity (AAI) values of 52–56.2%, which is below the proposed AAI threshold at the genus level and when compared to the known species of Geminicoccaceae. Colonies of strain SCSIO 64248T are circular, pink and convex. It was able to grow in the range of 4–37 °C, at pH 6.0–10.0 and in the presence of up to 8.0% (w/v) NaCl concentration. The major cellular fatty acid (>9%) was summed feature 8, C19 : 0 cyclo ω8c and C16 : 0, and the sole respiratory quinone was Q-10. The polar lipids were phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine and an unidentified phospholipid. Data of polyphasic characteristics revealed that strain SCSIO 64248T represented a novel species of a new genus within the family Geminicoccaceae, for which the name Marinivivus gen. nov. is proposed with the type strain of the type species Marinivivus vitaminiproducens SCSIO 64248T (=MCCC 1K08013T=KCTC 92503T).