Lidocaine, a widely used local anesthetic, has shown potential for drug repositioning in oncology due to its multi-targeted biological effects. There is evidence that lidocaine inhibits cancer cell proliferation, induces apoptosis, and suppresses metastasis through mechanisms including PI3K/AKT/mTOR pathway inhibition and voltage-gated sodium channel blockade. It also modulates the tumor microenvironment by reducing inflammatory signaling and cytokine release. Additionally, lidocaine demonstrates promise as a chemosensitizer by enhancing the efficacy of anti-cancer agents such as cisplatin and 5-fluorouracil, partly through inhibition of drug efflux transporters and epigenetic reactivation of tumor suppressor genes. This review analyzes current evidence on lidocaine as a potential anti-cancer drug and evaluates its efficacy and future potential. While preclinical findings are encouraging, clinical translation remains limited due to uncertainties in dosage, pharmacokinetics, and tumor heterogeneity. Further research is required to define its therapeutic role as an adjunct in cancer treatment.