Removal of organic dyes from wastewater by adsorption has advantages over conventional materials due to its low cost, abundance, adsorption capacity, and recycling. In this context, this study aims to evaluate the adsorption capacity of methylene blue (MB) in babassu coconut mesocarp commercial biochar. For this, biochar was characterized using physicochemical parameters, proximate analysis, specific surface area (S-BET), and surface functional groups. Batch tests were carried out to identify the influence of biochar dose, initial dye concentration, granulometric fraction, and time in the adsorptive process. Results were analyzed using kinetic and isotherm models. The S-BET of the commercial biochar was of 484.9 m(2) g(-1). The optimal conditions were using a biochar dose of 5 g L-1, initial dye concentration inferior to 300 mg L-1, and biochar granulometric fraction inferior to 0.15 mm. Elovich kinetic model (R-2 > 0.8742) was most suitable to represent the MB adsorption onto babassu coconut mesocarp biochar. The equilibrium adsorption data were best described by the Langmuir model (R-2 > 0.9897), with q(m) = 67.6 mg g(-1). This adsorbent is promising for its application in the treatment of wastewaters polluted by MB dye.