In this work, sodium bentonite (Bn) was used for removal of alizarin red S (ARS) from aqueous solution using batch technique. Fourier transform infrared spectroscopy and X-ray diffraction were used to characterize sodium bentonite. Different parameters that would affect ARS dye removal such as initial pH, contact time, initial ARS dye concentration, bentonite dose, and temperature were explored. The realized data from kinetic studies demonstrated the high fitness of pseudosecond-order kinetic model for better interpretation of the experimental data. The adsorption isotherms studies showed that Freundlich isotherm had a high correlation coefficient among the studied isotherm models. Thermodynamic studies proposed that ARS adsorption onto Bn was spontaneous in nature at the lower temperatures and exothermic.