In this study, the incipient wetness impregnation (IWI) method was used to prepare tin oxide nanoparticles supported on reduced graphene oxide nanosheets (SnO2/rGO). Characterize of catalyst composite were analyzed by X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR), Field emission scanning electron microscope (FESEM), energy dispersive X-ray spectroscopy (EDX), and Raman spectroscopy. The activity of the SnO2/rGO catalyst was evaluated in the catalytic oxidation process of dibenzothiophene (DBT) for modeled oil and diesel fuel in the presence of H2O2 as an oxidant. Optimum reaction conditions (the loading quantity of the tin oxide, the concentration of dibenzothiophene, the time of reaction, the temperature, the amount of oxidant, and the catalyst dosage) were investigated in a batch reactor. High-value of dibenzothiophene (DBT) removal from modeled oil samples was 79% at temperature = 60 ◦C, reaction time = 90 min, catalyst dosage = 0.04 g, amount of H2O2 = 0.375 mL, and 385 ppm concentration of dibenzothiophene. Catalyst activity at the same operating condition was also investigated for diesel fuel and the removal of sulfur was 41%