An alkaliphilic and moderately halophilic strain characterized by optimal growth at pH 9.0-10.0 and 7 % (w/v) NaCl, and designated B16-24T, was isolated from the rhizosphere soil of the bayonet grass Bolboschoenus maritimus at a soda pond in the Kiskunság National Park, Hungary. Cells of the strain were Gram-staining-positive, non-motile, straight rods, and formed central, ellipsoidal endospores with slightly swollen sporangia. The isolate was facultative anaerobic, catalase positive, oxidase negative, and contained a peptidoglycan of type A1γ based on meso-diaminopimelic acid. Menaquinone-7 (MK-7) was the predominant isoprenoid quinone, and anteiso-C15 : 0 the major cellular fatty acid. The DNA G+C content of strain B16-24T was 36.6 mol%. The 16S rRNA gene-based phylogenetic analysis revealed that the novel isolate had the greatest similarities to the type strains of Bacillus okhensis Kh10-101T (97.8 %), B. akibai 1139T (97.4 %), B. alkalisediminis K1-25T (97.3 %) and B. wakoensis N-1T (97.1 %). The DNA-DNA relatedness of strain B16-24T and the closely related Bacillus species ranged between 24±6 % and 35±3 %. The distinctive phenotypic and genetic results of this study confirmed that strain B16-24T represents a novel species within the genus Bacillus, for which the name Bacillus kiskunsagensis sp. nov. is proposed. The type strain is B16-24T (=DSM 29791T=NCAIM B.02610T).