Enhancing the sulfur resistance of ceria-based catalysts for the selective catalytic reduction of NOx with NH3 (NH3-SCR) has always been a major challenge. Herein, the NH3-SCR activity and sulfur tolerance of CeFeOx loaded with WO3 were improved by adjusting the precipitation sequence for Ce and Fe. W/Fe(f)-Ce catalysts (namely, first precipitate Fe and then Ce) presented the best sulfur tolerance due to their more uniformly dispersed Fe species, thereby giving rise to superior physicochemical properties, including smaller particle size, larger surface area, and stronger low-temperature redox capacity. Because of these factors, the contact between the catalyst and reactants was more thorough, the CeO2 sites were better protected, and the low-temperature reactivity for consuming NH4+ from ammonium bisulfate (ABS) was higher. This study suggests that doping with Fe can enhance the SO2 tolerance of Ce-based catalysts, and that the dispersion of Fe species is crucial, which provides guidance for preparing efficient and sulfur-tolerant NH3-SCR catalysts.