Super paramagnetic graphene oxide (GO) − Fe₃O₄ nanoparticle composites were prepared and charac-terized by conventional techniques such as XRD, SEM, EDX, FT-IR, Raman, XPS, DLS and zeta potential,etc. TEM studies have confirmed nanoparticle nature of the composites. The GO-magnetic nanoparticlecomposites can be dispersed in mildly acidic aqueous solutions and get concentrated in a small vol-ume under application of an external magnetic field. The composites were evaluated for the uptake ofactinide ions such as Am³⁺, UO₂²⁺, Th⁴⁺ and Pu⁴⁺ from mildly acidic aqueous solutions. Am³⁺ sorptionsharply increased with pH as the Kd values increased from about 10 at pH 1 to about 105 at pH 3 beyondwhich a plateau in the Kdvalues was seen. Eu³⁺ displayed nearly comparable uptake behaviour to thatof Am3+while the uptake of other metal ions followed the trend: Pu(IV) > Th(IV) » UO₂²⁺. The adsorptionbehaviour of Am³⁺ onto the graphene oxide − Fe₃O₄ nanoparticle composites fitted very well to the Lang-muir as well as Temkin isotherm models. The desorption rate (using 1 M HNO₃) was fast and reusabilitystudy results were highly encouraging. The very high uptake values suggest possible application of themagnetic nanoparticles in radioactive waste remediation in natural ground water.