A series of modified Zr–Mo oxide-based solid-acid catalysts were prepared by using the corresponding chlorides as oxide precursors and low-cost monofunctional carboxylic acids such as stearic acid, palmitic acid, myristic acid, and lauric acid as modifiers. The catalysts were characterized by thermogravimetric (TG) analysis, X-ray diffraction (XRD), Fourier transform infrared spectrometer (FTIR), ammonia temperature programmed desorption (NH3-TPD), scanning electron microscopy (SEM), and nitrogen adsorption–desorption. It was demonstrated that the modified catalysts possessed grainy structures and loose honeycombed surfaces that exhibit high acid intensity and surface area. In particular, Zr–Mo oxide modified with stearic acid showed the best catalytic performance for the esterification of oleic acid with methanol in comparison to other mixed metal oxides, and it was selected for further experimental studies. Under the optimal reaction conditions of molar ratio of 10:1 methanol/oleic acid, 4 wt % of catalyst loading, 2 h reaction time, and 180 °C reaction temperature, the conversion of oleic acid reached 94.2 %. Moreover, the employed solid-acid catalysts could also facilitate carbohydrate transformation, and could be easily separated from the reaction system and reused over at least six runs without significant loss of activity.