The current investigation focus on the use of brown alga Turbinaria conoides (TC) and polysulfone immobilized Turbinaria conoides (PITC) for the biosorption of rare earth element Thulium (Tm(III)) from aqueous systems. To attain the highest removal of Tm(III), the process parameters including the equilibrium pH, Tm(III) concentration and biosorption time were optimized. The characterization techniques were used to analyse the morphological features and elemental analysis of the biosorbents. The isotherm models of selective two and three parameters were subjected to inspect the equilibrium data. The biosorption data fitted to the different biosorption kinetic models. Results illustrated that both TC and PITC displayed higher biosorption capacity of 200.5 and 157.9 mg/g, respectively. Through kinetic trials, we identified delay in equilibrium attainment for PITC and the data were described with intraparticle diffusion model. TC and PITC presented comparable results with biosorption equilibrium attained in 200 min, optimum equilibrium solution pH 5.0 and exhibited maximum biosorption capacity for the initial Tm(III) concentrations of 500 mg/L. Recovery studies represented that the maximum desorption efficiency attained using 0.01 M HCl and PITC presented potential uptake capacity of Tm(III) during the entire 10 biosorption?desorption cycles.