A novel Gram-stain-positive, aerobic, catalase-positive, oxidase-negative, non-motile, and rod-shaped bacterium with ibuprofen-degrading capacity, designated DM4(T), was isolated from the sewage of a wastewater treatment plant (WWTP) in Guangzhou city, China. Strain DM4(T) grew optimally at 0% (w/v) NaCl, pH 5.0-7.0, and 30 degrees C, forming white colonies on trypticase soy agar. C-18:1 omega 9c, C-18:2 omega 9.12c and C-15:1 omega 10c were the predominant fatty acids. Results of 16S rRNA gene alignment and phylogenetic analysis indicated that strain DM4(T) belonged to the genus Patulibacter, was closely related to Patulibacter medicamentivorans DSM 25692(T) (98.5%) and P. brassicae KCTC 39817(T) (98.1%). Strain DM4(T) had a genome size of 5.33Mbp, and the DNA G + C content was 75.0%. The average nucleotide identity (ANI), average amino acid identity (AAI), and digital DNA-DNA hybridisation (dDDH) values between strain DM4(T) and P. medicamentivorans were 85.2%, 83.9%, and 29.0% respectively, while those between strain DM4(T) and P. brassicae were 78.5%, 71.3%, and 22.2%, respectively. Strain DM4(T) could significantly degrade ibuprofen by almost 80% after 84 h of incubation, and the degradation kinetics was well fitted with the first-order kinetics. Evidence from phenotypic, phylogenetic and chemotaxonomic analyses support that strain DM4(T) (= GDMCC 1.4574(T) = KCTC 59145(T)) represents a new species of the genus Patulibacter, for which the name Patulibacter defluvii sp. nov. is proposed.