Autism spectrum disorder (ASD) is characterized by persistent problems in speech, social interaction, restricted and repetitive behavior patterns, lack of interest, and intellectual disabilities. Currently, there is no effective treatment available for the core symptoms of ASD. Among various treatments, herbal pharmacological treatments have shown promising results with fewer side effects, especially cannabidiol (CBD) treatment for the core symptoms and co-morbidities of ASD. The current study was performed to explore the therapeutic potential of CBD oil supplementation against the valproic acid (VPA)-induced autism mouse model. The autism mouse model was developed by exposing albino BALB/c mouse fetuses to VPA (600 mg/kg) on gestational day 13. On postnatal day (PND)-21, the male pups from both control and diseased groups were further divided into the following treatment groups: (I) control saline group, (II) VPA-exposed group, (III) VPA + CBD oil (100 mg/kg/day/orally) group, and (IV) standard group of VPA + risperidone (RISP) (0.5 mg/kg/day/orally) for 3 consecutive weeks. VPA mice displayed autistic behaviors upon delivery, such as increased anxiety levels, delayed response to painful stimuli, and impaired social interaction. VPA mice also showed depletion of glutathione and other antioxidant levels. CBD oil improved these dysfunctions, as seen through biochemical analysis and morphological staining of the hippocampal region, prefrontal cortex, and Purkinje cells. These findings showed that CBD oil treatment significantly improved behavioral abnormalities and lowered the oxidative stress in the autistic mouse model by acting as an antioxidant.