This study demonstrates the use of walnut shell powder to eliminate Congo red dye from a water-based solution. If Congo red dye is present in water, it harms humans and aquatic organisms. This study examined four variables: the amount of adsorbent used (1, 2, and 3 g/100 ml), the initial concentration of dye (25, 32.5, and 45 mg/L), pH (2, 6, and 10), and the duration of contact time (90, 105, and 120 min). Batch adsorption experiments were conducted to investigate the impact of these parameters on the percentage of Congo red elimination. A study on optimization was performed utilizing Response Surface Methodology (RSM) through the application of Box-Behnken Design. The response was modeled using a quadratic function. The Congo red removal achieved the maximum percentage of 84.2% under the following operating conditions: 1 g of adsorbent, an initial dye concentration of 32.5 mg/L, pH 2, and a contact time of 105 min. The RSM predicted a CR removal percentage of 85% under the following conditions: 1 g of adsorbent dose, an initial dye concentration of 31.32 mg/L, pH 2, and a contact period of 92.47 min. This study suggests that walnut shell powder can be an inexpensive adsorbent to eliminate Congo red dye.