This study aimed to investigate the effect of cerium oxide nanoparticles (CeO2-NPs) on non-alcoholic fatty liver disease in postmenopausal obesity and the underlying mechanisms.64 adult female rats were allocated into Sham, ovariectomized (OVX), high-fat high-fructose dietfed- OVX (HFHF-OVX), and HFHF-OVX-CeO2-NPs-treated (CeO2-HFHF-OVX) groups. OVX and HFHF-OVX rats presented a significant increase in overall and visceral obesity, dyslipidemia, liver enzymes, serum malondialdehyde, liver TNF-α, TGF-β1 and free fatty acids, liver X receptor (LXR) expression associated with decreased serum total antioxidant capacity and liver short heterodimer partner (SHP) expression vs. Sham group. Also, histomorphometric studies displayed a significant higher scores of liver steatosis, inflammation and fibrosis. All these parameters were significantly improved by CeO2-NPs treatment in CeO2-HFHF-OVX vs. HFHF-OVX rats. Thus, CeO2-NPs treatment ameliorates liver steatosis, steatohepatitis, and fibrosis in postmenopausal obese rats via alleviation of obesity, dyslipidemia, modulating liver genes involved in lipid metabolism (LXR and SHP), decreasing liver lipogenesis besides its antioxidant and anti-inflammatory effects.