Corrosion causes significant damage to natural and historical monuments, increases the risk of equipment failures, and results in economic and environmental losses, thus driving the search for effective corrosion protection methods. Corrosion inhibitors are particularly valued for their effectiveness, environmental friendliness, affordability, and ease of extraction from renewable sources, contrasting with the high toxicity of many synthetic compounds. This study investigates the ethanol leaf extract of Dracaena arborea as a corrosion inhibitor for mild steel in sulphuric acid (H2SO4). The Dracaena arborea stems were dried, powdered, and soaked in various concentrations of acidic solution for 2–3 days. Coupons of mild steel were prepared and submerged in the experiment media for 7 days at temperatures between 30 °C and 60 °C, with their weights measured before and after to assess weight loss. Results showed that the corrosion inhibition efficiency (IE) increased with higher temperatures and concentrations but decreased over prolonged application. The maximum IE of 91.7% was achieved at a concentration of 1.5 g/l and a temperature of 60 °C, with the highest efficiency within the first 10 hours. The study concludes that Dracaena arborea leaf extract is an efficient corrosion inhibitor for mild steel in sulphuric acid. Additionally, using reconfigurable smart radio frequency biosensors for real-time dielectric monitoring can further improve the efficiency of corrosion inhibitors by reducing material waste and costs.