Diabetic foot ulcers (DFUs) are a significant complication of diabetes, presenting a substantial burden on patients and healthcare systems. These ulcers are challenging to treat with standard therapies, often leading to amputation. Ozone therapy offers a promising alternative due to its non-invasive, cost-effective, and low-risk nature. Ozone enhances cellular metabolism, exhibits antibacterial and antioxidant properties, and promotes wound healing through pathogen inactivation, vascular modulation, and immune activation. We report the case of a 32-year-old woman with type 1 diabetes and large progressive DFUs unresponsive to conventional treatments. Despite multiple debridements and antibiotics, her wounds worsened, and below-knee amputation was recommended. She sought ozone therapy as a last resort, undergoing eight weeks of local ozone gas application alongside comprehensive medical care. Remarkably, her ulcers fully healed, avoiding amputation. This case highlights ozone therapy's potential in managing advanced DFUs.