In the present study sodium hydroxide-modified Cellulose powder (SCP) is prepared from Cellulose powder (CP). The prepared sorbents are characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), Brunauer, Emmett, and Teller (BET), and N2 adsorption isotherm, point of zero charge. The batch adsorption method is applied to determine the optimum operational parameters for MB removal from aqueous solutions such as initial concentration of dye, pH, adsorbent dosage, and contact time. Kinetic models have been applied to test the experimental data to determine the mechanism of adsorption and its potential rate-controlling step. The obtained kinetics data revealed that the adsorption process of dye is more fitted to pseudo-second order than pseudo-first order. Equilibrium data showed that the adsorption of dye fitted well with Langmuir equilibrium isotherm model. Thermodynamic parameters ΔG°, ΔH°, and ΔS° parameters have been investigated. The negative values of ΔG° of all sorbents explain the spontaneous behavior of the adsorption process. The negative values of ΔH° can explain the exothermic behavior of all sorbents. The prepared Cellulose powder was successfully applied for the removal of dye at low concentrations from different water samples.