One of the main causes of acute liver failure is overdose with acetaminophen. Excessive consumption of acetaminophen leads to the production of NAPQI (N-acetyl-p-benzoquinone imine) through the activity of the enzyme cytochrome c oxidase. For this purpose, the effect of galangin nanoparticles with antioxidant activities will be evaluated for the treatment of acetaminophen-induced hepatotoxicity. In this study, after the synthesis of galangin nanoparticles and particle size determination, mice were divided into six groups. Before treatment, a single dose (350 mg/kg) of acetaminophen was administered by gavage in all groups. The activity of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), as well as biochemical factors FRAP and MDA in serum were measured and a histopathological study was performed. The prepared nanoparticles produced in this research were characterized by the SEM, DLS, and ZETA potential, and the average particle size was obtained in the range of 150 nm. Serum levels of liver enzymes (AST and ALT) in the nanoparticle group decreased significantly compared with the control group ( < 0.05). In the group without treatment, the activity of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) enzymes increased significantly compared with the treatment groups. Also, galangin nanoparticles, at a dose of 20 mg/kg, improve cell damage in hepatocytes and preserve the tissue structure of the liver. Galangin nanoparticles reduce the acetaminophen-induced hepatotoxicity by reducing the number of liver function indices. According to our findings, the liver-protective effects of the nanoparticle may be due to its antioxidant properties.