The depletion of conventional oil reserves has intensified the search for enhanced oil recovery (EOR) techniques. This research investigates the synthesis and application of magnetic graphene oxide nanoparticles (MGONs) for EOR in heavy crude oil reservoirs. MGONs were synthesized and stabilized in high-total dissolved solids (TDS) formation brine with xanthan gum polymer. Two coreflooding experiments were conducted on sandstone cores. The first experiment in high-permeability sandstone (843 mD) showed no formation damage; instead, permeability increased to 935 mD after MGON injection. Irreducible water saturation (Swirr) and residual oil saturation (Sor) were 25.1% and 31.5%, respectively. The second experiment in lower-permeability rock (231.3 mD) evaluated nanoparticle retention. Results showed 0.09511 mg of MGON adsorbed per gram of rock under dynamic conditions. Iron concentration in effluents stabilized after 3 pore volumes, indicating steady-state adsorption. The successful synthesis, stability in high-TDS brine, favorable interfacial properties, and positive effects observed in coreflooding experiments collectively highlight MGONs' potential as a viable solution for enhancing oil recovery in challenging reservoirs, without causing formation damage.