Summary: The study evaluates the adsorption capacity of methylene blue (MB) dye using a bio-composite of CNT-functionalized Moringa oleifera leaf powder (MOLP). Systematic optimization of adsorption parameters, including pH, dye concentration, temperature, and contact time, revealed the superior efficiency of CNT-MOLP compared to pristine MOLP. Characterization via SEM and FT-IR confirmed enhanced porosity and functional groups essential for dye binding. This work establishes CNT-MOLP as a sustainable, cost-effective adsorbent for industrial wastewater treatment applications.