In this work, lanthanum tungstate (La2(WO4)3) nanoparticles (NPs) were synthesized by facile sonochemical method (elmasonic P, under-sonication 37/100 kHz, ~60 W energy) and utilized as an electrode material for the selective and sensitive electrochemical determination of anti-scald inhibitor diphenylamine (DPA). The synthesized La2(WO4)3 NPs were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy dispersive x-ray spectroscopy (EDAX), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) analyses. The results revealed that the sonochemically synthesized La2(WO4)3 nanoparticles were with high crystallinity and uniformly distributed nanoparticles like structure. The as-prepared lanthanum tungstate NPs exhibited an excellent electrocatalytic behavior for DPA determination with the lowest detection limit of 0.0024 µM, wide linear range response of 0.01–58.06 µM and a remarkable sensitivity of 1.021 µA µM−1 cm−2. Furthermore, La2(WO4)3 NPs showed a good recovery to DPA in apple juice sample. Besides, the electrochemical mechanism of the DPA oxidation reaction was provided in detail.