Given the environmental and health risks posed by sulfur pollutants, their removal and the production of lower sulfur hydrocarbon fuels are essential. Therefore, oxidative desulfurization (ODS) technology has become crucial as it operates efficiently under moderate conditions. This study focused on the synthesis of a (Fe₂O₃ + NiO)/SiO₂ catalyst via incipient wetness impregnation, followed by drying at 120°C and calcination at 600°C. Several tests were performed on the catalyst before its application: BET, TGA, and SEM-EDX. The BET results showed a decrease in surface area from 166.47 to 149.57 m² g⁻¹ after metal loading, confirming the fixation of iron and nickel oxides on the silica support. XRD and FTIR analyses confirmed the formation of the metal oxide phases Fe₂O₃ and NiO, while preserving the amorphous nature of the silica. The prepared catalyst was tested in ultrasonic oxidative desulfurization of real diesel fuel containing up to 2018.14 ppm using hydrogen peroxide as the oxidizing agent. Various conditions were investigated, including the effect of temperature (25–75°C), reaction time (30–60 minutes), and ultrasonic intensity (80–100%). This was followed by ethanol extraction at a 1:1 diesel-to-solvent ratio. A sulfur removal efficiency of 90% was achieved. The study showed that the reaction followed a pseudo-first-order model with reaction rate constants of 0.0172, 0.0252, and 0.0400 min⁻¹ at 25, 50, and 75°C, respectively, with R² =0.98. The activation energy of the reaction was also calculated and found to be 14.50 kJ mol⁻¹, indicating the suitability of the kinetics and the efficiency of the catalytic activity under the influence of ultrasonication.