Ferroptosis, a form of iron-dependent cell death characterized by lipid peroxidation, has emerged as a promising strategy to overcome resistance to chemotherapy. This review explores the mechanisms of ferroptosis and its potential to reverse drug resistance in digestive system cancers. We summarize recent advances in understanding the GPX4-regulated pathway, iron metabolism, and lipid peroxidation as key drivers of ferroptosis. It also highlights the roles of tumor heterogeneity, tumor–stroma interactions, abnormal apoptosis, metabolic alterations, and the tumor microenvironment in drug resistance. Specific mechanisms of ferroptosis resistance in esophageal squamous cell carcinoma, gastric cancer, hepatocellular carcinoma, pancreatic ductal adenocarcinoma, and colorectal cancer are discussed, along with strategies to induce ferroptosis to reverse drug resistance. Future research should focus on translating these findings into clinical applications through targeted therapies and combination treatments to improve patient outcomes.