Bradyrhizobiumis a heterogeneous bacterial genus capable of establishing symbiotic associations with a broad range of legume hosts, including species of economic and environmental importance. This study was focused on the taxonomic and symbiovar definition of four strains – CNPSo 4026T, WSM 1704T, WSM 1738Tand WSM 4400T– previously isolated from nodules of legumes in Western Australia and South Africa. The 16S rRNA gene phylogenetic tree allocated the strains to theBradyrhizobium elkaniisupergroup. The multilocus sequence analysis (MLSA) with partial sequences of six housekeeping genes– atpD,dnaK,glnII,gyrB,recAandrpoB– did not cluster the strains under study as conspecific to any describedBradyrhizobiumspecies. Average nucleotide identity and digital DNA–DNA hybridization values were calculated for the four strains of this study and the closest species according to the MLSA phylogeny with the highest values being 95.46 and 62.20 %, respectively; therefore, both being lower than the species delineation cut-off values. ThenodCandnifHphylogenies included strains WSM 1738Tand WSM 4400Tin the symbiovars retamae and vignae respectively, and also allowed the definition of three new symbiovars, sv. cenepequi, sv. glycinis, and sv. cajani. Analysis of morphophysiological characterization reinforced the identification of four novel proposedBradyrhizobiumspecies that are accordingly named as follows:Bradyrhizobium cenepequisp. nov. (CNPSo 4026T=WSM 4798T=LMG 31653T), isolated fromVigna unguiculata;Bradyrhizobium semiaridumsp. nov. (WSM 1704T=CNPSo 4028T=LMG 31654T), isolated fromTephrosia gardneri;Bradyrhizobium hereditatissp. nov. (WSM 1738T=CNPSo 4025T=LMG 31652T), isolated fromIndigoferasp.; andBradyrhizobium australafricanumsp. nov. (WSM 4400T=CNPSo 4015T=LMG 31648T) isolated fromGlycinesp.