Cervical cancer remains a major threat to women’s health, with advanced cases often exhibiting recurrence and metastasis due to cancer stem cells driving therapy resistance. This study evaluated fenbendazole (FBZ), a repurposed veterinary anthelmintic, for its antitumor activity dual targeting cervical cancer cells (CCCs) and cervical cancer stem cells (CCSCs). CD133⁺CD44⁺ CCSCs were isolated from HeLa and C-33 A cell lines via immunomagnetic sorting and validated for stemness. Cell proliferation, cell cycle and apoptosis, and protein expression were detected by MST assay, flow cytometry, and Western blot analysis, respectively. FBZ dose-dependently inhibited proliferation, induced G2/M arrest, and triggered apoptosis in both CCCs and CCSCs. Mechanistically, FBZ upregulated cyclin B1 and phosphorylation of cdc25C-Ser198, while downregulating Wee1, phosphorylation of CDK1, and phosphorylation of cdc25C-Ser216, collectively enforcing G2/M blockade. In vivo, FBZ (100 mg/kg) significantly suppressed tumor growth in xenograft models without weight loss, contrasting with cisplatin-induced toxicity. Survival analysis revealed 100% survival in FBZ-treated mice versus 40% in cisplatin and 0% in untreated controls. These findings demonstrate FBZ’s unique ability to simultaneously target bulk tumor cells and therapy-resistant CCSCs via cell cycle disruption, supported by its preclinical safety and efficacy, positioning it as a promising therapeutic candidate for cervical cancer.