In the present study, in order to promote the practical application of the heterogeneous Fenton oxidation in wastewater treatment, Fe/ZrO2 catalyst was prepared and used in decolorization of Direct Orange 26 (DO26) over a wide pH range. Within this scope, Fe/ZrO2 catalyst has been synthesized by co-precipitation method and characterized by XRD, BET, SEM and XRF techniques. To investigate the activity of the catalyst in the decolorization process, the effects of different parameters such as percentage of iron ions loading on the catalyst and the dosage of catalyst, contact time, solution pH, and initial concentration of H2O2 and dye on the decolorization efficiency of the process were studied. The best reaction conditions were found to be an initial pH of 4.0 when the dosage of catalyst, was 10.0 g/L with 6% Fe content, [H2O2] of 5 mM, [D026](degrees). of 100 mg/L, and a stirring speed of 140 rpm at 25 degrees C. At suitable conditions, a 98.7% decolorization efficiency of DO26 was achieved within 90 min of the reaction. Stability and reuse of the catalyst were also tested. Fe/ZrO2 was demonstrated to have good stability and reusability, indicating it could be a suitable heterogeneous Fenton like a catalyst in a wide range of pH.