The batch removal of copper (II) ions from aqueous solution and wastewater using the activated carbon prepared from Gracilaria by acid decomposition was investigated. The effect of pH, biosorption time,adsorbent dose, and metal ions concentration, were considered. The most effective pH was found to be 4.0. The biosorption capacities were solution pH dependent and the maximum uptake for copper with initial concentration 70, 100 and 150 mg l-1 at pH 4.0 were obtained 95.53, 93.72 and 88.84%, respectively. The total metal ions biosorption occurs within 2 h. The equilibrium adsorption data fitted to Langmuir and Freundlich isotherm models. Both the models represent the experimental data satisfactorily. The adsorption follows second order kinetic. This study shows the benefit of using activated carbon from marine red algae as a low cost sorbent for the removal of copper from aqueous solution wastewater