Zinc oxide nanoparticles (ZnO NPs) were synthesized via a precipitation method using NaOH as the precipitating agent and ZnSO₄·7H₂O as the starting material. The synthesis process was conducted at the Department of Physics, University of Agriculture, Faisalabad. The resulting ZnO NPs were dried at 80°C and calcined at 500°C, yielding monodisperse particles with a wurtzite structure and an average crystallite size of 12 nm. Characterization techniques including UV-Visible absorption spectroscopy, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) confirmed the successful synthesis, revealing spherical morphologies and strong UV absorption properties. The study further explored the application of these ZnO NPs as an innovative nutrient management strategy to enhance maize (Zea mays L.) growth under salinity stress—a major challenge in agriculture. Hydroponic experiments were conducted to assess the impact of different Zn concentrations (2, 5, 10, 25 ppm) in both nanoparticle and conventional fertilizer forms under saline conditions (10 mM NaCl). The results demonstrated that ZnO NPs significantly outperformed conventional Zn fertilizers, enhancing biomass accumulation, morphological attributes, chlorophyll content, and water retention in maize. Optimal ZnO NP concentration (10 ppm) provided notable improvements in plant growth while minimizing the toxic effects of excessive zinc. These findings highlight the potential of ZnO NPs as a superior and sustainable approach to mitigating salinity stress in maize, offering valuable insights for future research and practical applications in crop management.