A taxonomic study was conducted on two Gram-reaction-positive, catalase-negative, irregular short-rod-shaped or coccoid lactic acid bacteria, designated strains SG25(T) and SG23, that were isolated from grains of fermented Japanese rice (Oryza sativa L. subsp. japonica). A phylogenetic analysis based on 16S rRNA gene sequence data clearly showed that the strains belonged to the genus Weissella and were most closely related to Weissella soli LMG 20113(T) (with a sequence similarity of 96.9 % for each novel strain). The peptidoglycan of each strain contained the amino acids glutamic acid, lysine, serine and alanine in a molar ratio of 1.0 : 1.2 : 0.5 : 3.0, respectively. On the basis of the unusual phenotypic characteristics of the novel strains and the low levels of DNA-DNA relatedness recorded between each novel strain and Weissella soli JCM 12536(T), strains SG25(T) and SG23 represent a single novel species in the genus Weissella, for which the name Weissella oryzae sp. nov. is proposed. The type strain is SG25(T) (= JCM 18191(T) = DSM 25784(T)).