Bacterial strain M19T was isolated from the gut of a wood-feeding termite, Nasutitermes hainanensis. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain M19T was related to members of the genus Lactococcus, with sequence similarities ranging from 84.8 to 95.5 %. Comparison of housekeeping gene ropB sequences revealed that strain M19T was well separated from Lactococcus fujiensis JCM 16395T and Lactococcus hircilactis 117T. The isolate was Gram-stain-positive, catalase-negative and non-motile. Cells were coccoid or ovoid-shaped, and occurred singly, in pairs or as short chains. Growth of strain M19T occurred at 10-40 °C and at pH 5.0-7.5. The DNA G+C content of strain M19T was 39.6 mol% and the major fatty acids were C16 : 0, cyclo-C19 : 0ω8c, C18 : 1ω9c, summed feature 7 and summed feature 8. Based on the phylogenetic, chemotaxonomic and phenotypic data presented, strain M19T represents a novel species of the genus Lactococcus, for which the name Lactococcus nasutitermitis sp. nov. is proposed. The type strain is M19T ( = CGMCC 1.15204T = NBRC 111537T).