The removal of Mn (II) ions by adsorption using biomass derived from Terminalia catappa fruit powder was studied in a batch system. The influence factor such as pH, initial concentrations, biosorbent dosage and contact time were also studied. Result showed that optimum pH for adsorption was 6, optimum contact time was 15 minutes and initial concentration of Mn (II) was 6900 mg/L. The effect of biosorbent dosage for Mn (II) ions removal and adsorption capacity also investigated. The optimum amount of T. catappa fruit powder biomass to remove Mn (II) ions was 1 g, and able to remove Mn (II) ions up to 75.22%. The biosorption data were fitted to Langmuir isotherm with R2 = 0.9810. Characterization of T. catappa fruit powder biomass was analyzed using Fourier Transform Infra Red (FTIR) spectroscopy and active functional group that might be involved in adsorption were –NH stretching and carbonyl groups. The surface analysis before and after adsorption was analyzed using Scanning Electron Microscope (SEM). This research indicated that the adsorbent has a great potential to remove Mn (II) from aqeous media contributing to an eco friendly technology for efficient bioremediation