Mercury is given particular attention, because of its ability for detrimental impacts on both human and animal health. Therefore it is, claimed that it accumulates in the liver, causing liver toxicity, and tissue damage. Consequently, it was intended for the current research to explore the potential antioxidant activity of CoQ10 against HgCL2-induced hepatotoxicity. Twenty-eight male albino rats were split into four groups: the control group, given saline; the CoQ10 group, given coenzyme Q10 (10mg/kg bwt); the HgCL2 group, given mercuric chloride (1mg/kg bwt); and the co-treated group, given coenzyme Q10 group+HgCL2 group (10mg/kg bwt , 1mg/kg bwt respectively). All treatments were received orally for 4 weeks. The HgCL2 group had significantly higher serum concentrations of the enzymes alanine aminotransferase (ALT); aspartate aminotransferase (AST); alkaline phosphatase (ALP)and lactate dehydrogenase (LDH), While total protein and albumin were significantly decreased. The Rats also showed a significant increase in mercury concentration and exhibited a notable spike of lipid peroxidation levels with concurrent declines in antioxidant enzymes (GSH), also our result was confirmed by histopathological examination of liver tissues. Treatment with CoQ10 produces protection against hepatotoxicity caused by HgCL2.CoQ10 mitigates biochemical parameters, histopathological changes, and mercury buildup in liver tissues. In conclusion, CoQ10 could be the best choice to counteract the oxidative damage produced by mercury exposure.