A novel BiVO4/FeMn layered double hydroxide (LDH) nanocomposite was fabricated and applied for green and efficient ultrasound-assisted oxidative desulfurization (UAODS) of real fuel (hydrotreated oil). The physicochemical properties of the prepared BiVO4/FeMn LDH nanocomposites are elucidated using techniques such as XRD, FT-IR, BET, SEM, XPS, Raman, and TGA. The desulfurization results revealed that both BiVO4 and FeMn LDH were crucial in the UAODS process in the presence of H2O2 as a green oxidant and acetonitrile as an extracting solvent. The desulfurization activity was optimized by varying the process conditions (time, catalyst weight, type of oxidant, O/S molar ratio, ratio of solvent to oil, and type of sonicator). The prepared nanocomposite exhibited remarkable desulfurization performance, reaching up to 99.8% under the optimized reaction conditions. Moreover, the catalyst exhibited high stability and could be reused four times without a notable decline in the performance. Significantly, this research reveals the robustness of the newly synthesized nanocomposite for efficient UAODS in a short time and low catalyst dosage. The proposed desulfurization mechanism was investigated.