Application of organic-inorganic nanocomposite membranes for water treatment is exceptionally growing owing to their tunable functionalities in addition to their enhanced permeation and antifouling propensity. In the present work, novel nanocomposite polyethersulfone (PES) membrane was synthesized using antimony-doped fin oxide (ATO) nanoparticles (NPs) via phase separation technique. It was found that the modified PES-ATO nanocomposite membranes exhibited significantly higher fouling resistance and larger permeate flux recovery ratio when tested with oil sands produced water than unmodified PES membranes. Furthermore, the PES-ATO membranes provided 40% more organic matter removal compared to the base PES membranes. However, the addition of the ATO NPs to the PES casting solution resulted in tighter membranes with denser skin layer and lower average pore size. By evaluation of the surface potential and wettability of the membrane, it was revealed that the higher antifouling propensity and larger separation efficiency of the nanocomposite membrane originate primarily from their higher surface hydrophilicity and lower porosity which resulted in about 99% flux recovery during the filtration of oil sands produced water. Furthermore, the developed PES-ATO nanocomposite membranes demonstrated larger electrical conductivity and higher thermal stability compared to pristine PES membranes. The tunable antifouling propensity along with enhanced thermal stability and electrical conductivity suggest the promising potential of the developed PES-ATO nanocomposite membrane to be employed in advanced membrane technologies using external stimuli such as electric field, or thermal gradient for the purification of industrial produced water.