This study evaluated the efficiency of the heterogeneous Fenton process using magnetic activated carbon catalyst produced from date palm waste in removing direct dye from aqueous solutions. The experimental runs and optimal conditions for the effect of contact time, solution pH, catalyst dose, and persulfate dose were determined based on the Box-Behnken design under response surface methodology (RSM). FTIR, FESEM, XRD, EDS, BET, and VSM analyses were used to investigate the characteristics of the catalyst. The analysis of variance (ANOVA) verified that the selected statistical model with R2 0.95, p-value<0.0001, and F-value 58.67 was significant. The results of optimal conditions showed that at a dye concentration of 50 mg/L, catalyst dose 0.96 g/L, persulfate dose 9.7 mM, pH 7 and contact time 84 min, maximum removal efficiency of DR80, DB80, DBw103 and COD was 92.69, 97.07, 73.85, and 60%, respectively. After five cycles of catalyst regeneration, the results showed that the catalyst could be utilized several times effectively for dye removal.