In addressing the gap in sustainable utilization of industrial by-products and the limited exploration of natural antioxidants in nanoparticle synthesis, this study focused on synthesizing magnesium oxide (MgO) nanoparticles using by-products from Melaleuca leucadendra essential oil extraction. The research aimed to evaluate the feasibility of manufactoruing metal nanoparticles with agricultural waste and assesing their properties. The study first tested the antioxidant properties of the water extract of Melaleuca leucadendra leaves, a manufacturing waste from the Melaleuca leucadendra essential oil extraction process, using DPPH and FRAP assays. Green synthesis methods was employed to produce the nanoparticles. The production and properties of the particles were characterize with UV-VIS . Our results indicated that the MgO nanoparticles exhibited antioxidant activity. This study suggests a viable, eco-friendly approach for the utilization of agricultural waste from the Melaleuca leucadendra essential oil extraction.