Background <p>Carotid atherosclerosis (CAS) is a major cause of ischemic stroke. Ferroptosis-related proteins glutathione peroxidase 4 (GPX4), arachidonate 15-lipoxygenase (ALOX15), and ferroportin-1 (FPN1) may be involved in atherosclerotic processes, but their clinical relevance in CAS remains unclear.</p> Objective <p>To examine the associations of serum GPX4, ALOX15, and FPN1 with CAS severity and evaluate their discriminatory performance for severe carotid stenosis.</p> Methods <p>This cross-sectional observational study included 280 CAS patients classified into non-severe (<i>n</i> = 207) and severe (<i>n</i> = 73) stenosis groups. Serum GPX4, ALOX15, and FPN1 were measured by ELISA. Group differences were analyzed, ROC analysis assessed discriminatory performance, and logistic regression identified factors associated with severe CAS.</p> Results <p>Severe CAS patients were older and had higher proportions of diabetes, multiple plaques, and prior stroke. They also showed higher TC, LDL-C, hs-CRP, and IL-6, lower HDL-C, lower serum GPX4 and FPN1, and higher ALOX15. The AUCs were 0.721 for GPX4, 0.698 for FPN1, and 0.869 for ALOX15. The biomarker model yielded an AUC of 0.914. The combined model including clinical variables and the three biomarkers yielded an AUC of 0.991 and outperformed the clinical model alone. In multivariable analysis, age, HDL-C, Z-ln(hs-CRP), Z-ln(IL-6), GPX4, and ALOX15 remained independently associated with severe CAS.</p> Conclusion <p>Serum GPX4, ALOX15, and FPN1 were associated with CAS severity and provided additional discriminatory information for severe carotid stenosis in this cohort. Further longitudinal validation is needed.</p>