Background: Sarcandra glabra (S. glabra), a traditional Chinese medicine (TCM), has demonstrated significant anticancer activity; however, the underlying mechanisms have not yet been fully elucidated. Purpose: This study aimed to investigate the effects of S. glabra on lung cancer and to explore its underlying mechanisms. Methods: The chemical profile of S. glabra was analyzed via ultrahigh-performance liquid chromatography coupled with mass spectrometry (UPLC-MS). The effects of S. glabra on the viability, proliferation, apoptosis, migration, and invasion of lung cancer cells were assessed via CCK8, colony formation, flow cytometry, scratch, and Transwell assays. In vivo anticancer activity was evaluated in an LLC mouse model. Proteomic analysis was performed to identify key molecules and pathways in S. glabra-treated LLC cells. The expression of ferroptotic proteins and associated cellular events were examined via western blotting, ROS production, iron accumulation, and lipid peroxidation assays. Immune modulation in tumor-bearing mice was evaluated by detecting immune cells and cytokines in the peripheral blood and tumor tissue. Results: Our analysis quantified 1997 chemical markers in S. glabra aqueous extracts. S. glabra inhibited the viability and proliferation of lung cancer cells and induced cell cycle arrest and apoptosis. Scratch and Transwell assays demonstrated that S. glabra suppressed the migration and invasion of lung cancer cells. Oral administration of S. glabra significantly inhibited tumor growth in LLC tumor-bearing mice. Proteomic analysis revealed that S. glabra upregulated the expression of the HMOX1 protein and activated the ferroptosis pathway. Consistent with these findings, we found that S. glabra triggered ferroptosis in lung cancer cells, as evidenced by the upregulation of HMOX1, downregulation of GPX4 and ferritin light chain proteins, iron accumulation, increased ROS production, and lipid peroxidation. Furthermore, S. glabra demonstrated immunostimulatory properties in LLC tumor-bearing mice, leading to increased populations of immune cells (NK cells) and elevated cytokine levels (IL-2). Conclusion: This study is the first to demonstrate that S. glabra induces ferroptosis in lung cancer cells by regulating HMOX1, GPX4, and FTL. These findings provide a robust scientific basis for the clinical application of S. glabra in lung cancer treatment.