<p>The production of nanomaterials using organic chemical compounds can pose considerable environmental risk. It opens a pathway toward a sustainable green synthesis approach that is biologically safe, eco-friendly, and efficient in reducing biological impacts. In this study, a green synthesis approach was proposed for the fabrication of MgO nanostructures by utilizing kiwi peel extract as a bio-template. The fabricated MgO nanostructure was characterized in terms of its optical, morphological, and structural features using a range of analytical techniques. The band observed above 3000&#xa0;cm⁻¹ in the FTIR spectrum is assigned to the stretching vibrations of the phenolic and flavonoid constituents in the kiwi peel extract. Moreover, the formation of the Mg–O bond in the MgO nanostructure is confirmed by the appearance of the new absorption peak at 599&#xa0;cm⁻¹ in UV absorption spectra. The result of the XRD examination revealed that MgO nanostructures exhibit a crystalline cubic phase. The crystallite size of the fabricated material was estimated by employing the XRD data, with an average value of 4.18&#xa0;nm. The SEM examination of the synthesized MgO nanostructure shows a spherical shape with a particle size ranging from 80 to 90&#xa0;nm. Apart from its physicochemical properties, the synthesized MgO nanostructure exhibits outstanding photocatalytic performance, attaining nearly 47.94% and 41.03% degradation of aspirin and cefixime, respectively, within 120&#xa0;min under optimal conditions of the irradiation time, pH, antibiotic concentration, and catalyst dosage. The findings of the present investigation suggest that the bio-fabricated MgO nanostructure displays significant photocatalytic performance in the degradation of the antibiotic contaminants. This high efficiency emphasizes its strong potential for real-world wastewater treatment applications, providing a sustainable and cost-effective strategy for eliminating harmful antibiotics from contaminated water.</p>