MG, an organic compound composed of triphenyl methane, is often widely used in various industries, especially in the food, pharmaceutical and textile industries. This study emphasizes the green synthesis of novel magnetic iron oxide nanoparticles-loaded sawdust carbon (Fe 3 O 4 /SC) and their effect on the removal of MG from the aqueous solution. To obtain the optimum conditions of MG removal using the Box–Behnken model, the independent variables such as the initial MG concentration (10–100 mg/L), pH (3–9), reaction time (10–60 min), and Fe 3 O 4 /SC nanocomposites dose (0.2–1 g/L) were experimented. According to the quadratic model, the highest removal rate (89.22%) was found at the pH of 8.62, the contact time of 59.86 min, the Fe 3 O 4 /SC ncs dose of 0.59 g /L and the MG level of 17.62 mg/L. The MG removal rate follows the pseudo-second-order model and the Langmuir model. The maximum absorption capacity for MG was 41.66 mg/g. These findings suggest that the Fe 3 O 4 /SC ncs has a significant potential for the MG adsorption from aqueous solution.