The current study aimed to estimate in vitro antioxidant effect of Astragalus davisii (A. davisii) extract. Further, the possible protective effect of A. davisii against paracetamol (PCM)-induced liver injury was assessed in rats. A. davisii was tested for its antioxidant activity using DPPH radical scavenging assay. The hepatoprotective potential of the extract was assessed in rats following oral administration for 7 days. Liver injury was induced in rats following oral administration of PCM overdose. Hepatic biomarkers; alanine-aminotransferase, aspartate-aminotransferase, alkaline-phosphatase, gamma-glutamyl transferase and bilirubin were increased, while total protein and albumin were reduced in PCM control animals. Additionally, the activities of superoxide dismutase (SOD), catalase and glutathione-peroxidase (GPx) and the levels of glutathione were significantly declined, while levels of hepatic malondialdehyde (MDA) were significantly elevated in PCM alone treated rats. Oral administration of A. davisii (400 mg/kg) prior to PCM inhibited the elevation in the levels of liver damage markers in serum and protected against oxidative stress. Histopathological remarks confirmed the hepatoprotective potential of the extract. The results suggest that A. davisii extract at 400 mg/kg protects liver against injury induced by PCM overdose.