The goal of this study was to survey the feasibility of the biosorption of Reactive Black 5 (RB5) from aqueous solutions using biomass prepared from potato peel waste. Adsorption isotherms were constructed, and the kinetics of dye adsorption were studied. Langmuir and Freundlich isotherms were constructed, and pseudo-first order, pseudo-second order, and modified pseudo-first order kinetic models were studied. Maximum adsorption (85.5%) was observed at a pH of 3, and uptake decreased with increasing pH. The biosorption of RB5 increased with increasing contact time and reached equilibrium after two hours. RB5 removal efficiency decreased with an increase in the initial dye concentration, but the uptake of dye increased. Adsorption data conformed to the Langmuir isotherm model and pseudo-first order kinetics.