In the present study, we evaluated the antioxidant potential of Artemisia campestris essential oil (ACEO) and the possible protective effects against deltamethrin induced hepatic toxic effects. The ACEO showed radical scavenging activity with IC50 = 47.66 ± 2.51 µg/ml, ferric reducing antioxidant power (FRAP) potential (EC50 = 5.36 ± 0.77 µg/ml), superoxide scavenging activity (IC50 = 0.175 ± 0.007 µg/ml) and ˙OH scavenging activity (IC50 = 0.034 ± 0.007 µg/ml). The obtained results of phenolic profile demonstrated that phenolic compounds are the major contributor to the antioxidant activity of ACEO. GC-MS analysis revealed the presence of 61 components in which monoterpene hydrocarbons constitute the major fraction (38.85%). In in vivo study, deltamethrin exposure caused an increase of serum AST, ALT and ALP activities, hepatic malondialdehyde (MDA) (measured as TBARS) and conjugated dienes markers of lipid peroxidation (LPO), while antioxidant enzyme activities (SOD, CAT and GPx) decreased significantly. Furthermore, it induces DNA damage as indicated by DNA fragmentation accompanied with severe histological changes in the liver tissues. The treatment with vitamin E or ACEO significantly improved the hepatic toxicity induced by deltamethrin. It can be concluded that vitamin E and ACEO are able to improve the hepatic oxidative damage induced by deltamethrin. Therefore, ACEO is an important product in reducing the toxic effects of deltamethrin.