Obesity is recognized as a metabolic disorder, and its treatment and management pose ongoing challenges worldwide. Hawthorn, a traditional Chinese herb used to alleviate digestive issues and reduce blood lipid levels, has unclear mechanisms of action regarding its active components in the treatment of obesity. This study investigated the anti-obesity effects of vitexin, a major flavonoid compound found in hawthorn, in high-fat diet (HFD)-induced C57BL/6 mice. The results demonstrated that vitexin significantly reduced body weight, liver weight, blood lipid levels, and inflammatory markers in obese mice, while also inhibiting hepatic lipid accumulation. Mechanistic studies revealed that vitexin likely suppresses adipogenesis by modulating the PI3K-AKT signaling pathway, as evidenced by reduced expression of PI3K, phosphorylated AKT, phosphorylated mTOR, and SREBP-1c in the livers of vitexin-treated obese mice. Additionally, vitexin inhibited NFκB expression by regulating IκBα phosphorylation, thereby alleviating obesity-induced liver injury. These findings suggest that vitexin may be the primary active component in hawthorn responsible for reducing blood lipid levels, highlighting its potential in the treatment of obesity and its associated metabolic disorders.