A Gram-stain-positive, facultatively anaerobic, non-motile, endospore-forming and rod-shaped bacterium, occurring singly or in pairs, designated TB2019T, was isolated from environmental monitoring samples of corridor air collected at the Tianjin Institute for Drug Control, Tianjin Province (PR China). The isolate was able to grow at 15–40 °C (optimum growth at 37 °C), pH 6.0–8.0 (pH 7.0) and in the presence of 0–2% (w/v) NaCl (0% NaCl). Comparison of 16S rRNA gene sequences indicated that TB2019T was most closely related to Paenibacillus typhae CGMCC 1.11012T (98.63%), Paenibacillus albidus Q4-3T (98.19%), Paenibacillus borealis DSM 13188T (97.55%), Paenibacillus helianthi P26ET (97.33%) and Paenibacillus odorifer DSM 15391T (97.19%). The digital DNA–DNA hybridization and the average nucleotide identity values between TB2019T and the five type strains mentioned above ranged from 20.7 to 25.0% and 75.2 to 81.3%, respectively, and the genomic DNA G+C content was 49.52 mol%. The diagnostic cell-wall sugar was ribose, and the diagnostic amino acid was meso-diaminopimelic acid. The polar lipids of TB2019T included diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, three unidentified aminophospholipids and one unidentified phospholipid. MK-7 was the predominant menaquinone, and anteiso-C15:0 (30.6%) was the major fatty acid. Based on the polyphasic taxonomic data, strain TB2019T represents a novel species of the genus Paenibacillus , for which the name Paenibacillus tianjinensis sp. nov. is proposed. The type strain is TB2019T (=CICC 25065T=JCM 34610T).