A novel actinobacterium, designated strain SCSIO 10480(T), was isolated from a gorgonian coral sample of Anthogorgia sp. Phylogenetic and phenotypic properties of the organism supported that it belonged to the genus Janibacter. Phylogenetic analysis indicated that the levels of 16S rRNA gene sequence similarity between strain SCSIO 10480(T) and other type strains of recognized members of the genus Janibacter were 96.0-97.8 %. Growth in the presence of up to 17 % (w/v) NaCl and optimally at pH 9.0-10.0 was a distinctive characteristic of strain SCSIO 10480(T). Other biochemical and physiological properties and the fatty acid profile also differentiated the isolate from other members of Janibacter species. Based on the results obtained in this study, we propose that strain SCSIO 10480(T) should be classified within a novel species of the genus Janibacter, for which the name Janibacter alkaliphilus sp. nov. is proposed, with SCSIO 10480(T) (=CCTCC AB 2011027(T) = DSM 24723(T)) as the type strain.