Sweet corn (Zea mays L. Saccharata Sturt) seeds, like other crops, often experience deterioration during storage, which can negatively impact their germination and performance. This study investigated the impact of hydrogen peroxide (H₂O₂) priming on the germination, vigour, and antioxidant activities of deteriorated sweet corn seeds. A one-year-old GSH1005Y sweet corn seed sample, with a germination of 48%, was primed in H₂O₂ concentrations ranging from 1 mM to 20 mM for 24 hours, followed by drying. Seed germination and vigour were assessed through germination and electrical conductivity (EC) tests. Antioxidant activities, including catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), and malondialdehyde (MDA) content, were also evaluated. Results showed that priming with H₂O₂ significantly improved seed germination. Seeds treated with 10 mM H₂O₂ achieved 69% germination, a 21% increase compared to the untreated seeds. Priming with 5 mM and 7.5 mM H₂O₂ also enhanced germination (67% and 66%, respectively). Seedling performance was best at 10 mM H₂O₂, reducing mean germination time by 16%, increasing the coefficient of velocity of germination, and resulting in longer seedlings and higher shoot dry weight (45.5% increase over untreated seeds). Higher concentrations (12.5 mM to 20 mM) did not improve performance and negatively affected seedlings. H₂O₂ priming increased SOD activity while reducing MDA content, indicating less oxidative stress. EC measurements showed improved membrane integrity, especially at 10 mM H₂O₂. In conclusion, H₂O₂ priming at 10 mM for 24 hours significantly improved seed quality and vigour, offering a cost-effective solution for enhancing deteriorated seeds.