In this study, chemically modified lignin and alginate (Alg) hybrid spherical adsorbents exhibiting highly effective adsorption performance for cationic dyes were simply prepared. Carboxylated lignin (C-Lig) was prepared by simple peracetic acid oxidation. Thereafter, through encapsulation of C-Lig into Alg beads was conducted. As the encapsulated amount of C-Lig increased, a higher methylene blue (MB) removal capacity was observed due to the introduction of carboxylated anions on the surface. The adsorption isotherm of Alg/C-Lig beads followed the Langmuir model and exhibited a high monolayer maximum adsorption capacity (qm) of 613 mg/g due to the driving force which is electrostatic interaction between the cationic dye and the anionic group of C-Lig. According to intraparticle diffusion theory, the adsorption behavior proceeded in surface adsorption and internal diffusion during 6 h of the adsorption process. Desorption of MB molecules was found to occur easily via a change in only the pH condition of the solution, and it was possible to maintain over 80% of stable adsorption efficiency even after 5 repeated adsorption/desorption cycles. The facile fabrication process of the Alg/C-Lig beads and superior MB removal performance imply that the Alg/C-Lig beads show a high possibility to purify dye wastewater especially cationic dye molecules.