A Gram-stain-negative, non-spore-forming, non-motile, short-rod-shaped, and aerobic bacterial strain (designated L72^T) was isolated from propylene oxide saponification wastewater activated sludge obtained from a wastewater treatment facility in Binzhou (Shandong Province, PR China). Strain L72^T grew between 25 and 40 °C (optimum growth at 30 °C). The pH range for growth was between 6.0 and 8.0 (optimum growth at pH 7.0). The range of NaCl concentrations for the growth of strain L72^T was 0–3.0 % (w/v), with optimum growth at 1.0–2.0 % (w/v). The major cellular fatty acids of strain L72^T were C_19:0cyclo ω8c, C_18:1ω7c, iso-C_15:0, and anteiso-C_15:0. Strain L72^T contained Q–10 as the predominant respiratory quinone. The polar lipid profile was composed of Phosphatidylcholine, Glycolipid, Aminophospholipid, Phosphatidylethanolamine, Phosphatidylserine, Phosphatidyldimethylethanolamine, one unknown lipid (L) and two unidentified Phospholipids (PL). Genome sequencing revealed a genome size of 4,703,686 bp and a G + C content of 69.0 mol%. The 16S rRNA gene sequence similarities of strain L72^T with other species were less than 94%. Phylogenetic analyses based on 16S rRNA gene sequences and genome data, revealed that strain L72^T formed a distinct phylogenetic lineage within the order Hyphomicrobiales, separating them from members of all families. Strain L72^T showed 70.7% average nucleotide identity and 18.6% digital DNA-DNA hybridization identity with the closely related species Rhodoligotrophos defluvii. Based on the phenotypic, phylogenetic and chemotaxonomic data, a new family Propylenellaceae fam. nov. comprising the genus Propylenella gen. nov. and species Propylenella binzhouense sp. nov. is proposed. The type strain is L72^T (= CCTCC AB 2019081^T = KCTC 72254^T).