Through disease investigation of Asian seabass from a coastal fish farm in 2015 in Singapore, a novel birnavirus named Lates calcarifer Birnavirus (LCBV) was isolated in Bluegill Fry (BF-2) cell line. The LCBV-infected BF-2 cell line showed cytopathic effects such as rounding and granulation of cells, localized cell death and detachment of cells. The propagated virus, when injected intraperitoneally into naïve Asian seabass under experimental conditions, induced lesions similar to fish naturally infected with LCBV. Morphology of LCBV, visualized under TEM, revealed icosahedral particles around 50 nm in diameter. Chloroform and BUDR sensitivity assays confirmed the virus to be a non-enveloped RNA virus. Further genome analysis using NGS identified the virus to be a birnavirus with two genome segments. Phylogenetic analyses revealed that LCBV is more closely related to the Blosnavirus genus than to the Aquabirnavirus genus within the Birnaviridae family. These findings revealed the presence of a novel birnavirus that could be linked to the diseases observed in the Asian seabass from the coastal fish farms in Singapore. This calls for more studies on disease transmission, pathogenicity and epidemiology of this novel virus. The gene sequences data obtained from the study can be used for development of PCR-based diagnostic test methods.