Purpose <p>Lead (Pb) contamination in agricultural soil poses a severe threat to global food security and human health that needs urgent attention. This study aimed to evaluate the potential of foliar-applied green-synthesized zinc oxide nanoparticles (ZnONPs) for the mitigation of lead-induced stress in two maize (<i>Zea mays</i> L.) varieties (V1 = Cimmyt-Pak and V2 = Yh-5427).</p> Methods <p>A pot experiment was conducted using three ZnONPs concentrations (0, 150, and 300 mg L^− 1) applied through the foliar route to assess the physiological, biochemical, and growth responses of maize plants under different Pb levels in the growth medium (0, 250, 500&#xa0;mg kg^− 1).</p> Results <p>Application of ZnONPs, particularly at 300 mg L^− 1, significantly enhanced the plant height (56.6% in V1, 88.9% in V2), chlorophyll contents (79.3% in V1, 38.2% in V2), biomass accumulation, and gas exchange parameters under Pb stress. ZnONPs reduced the electrolyte leakage and hydrogen peroxide (H₂O₂) levels in leaves of plants while enhancing the antioxidant enzymatic activities. Application of ZnONPs reduced Pb concentrations in plants while enhancing the zinc (Zn) concentration in plant tissues compared to the respective Pb treatments without nanoparticles.</p> Conclusion <p>Foliar application of green-synthesized ZnONPs may offer a promising approach to improve plant tolerance to Pb stress while enhancing crop productivity in Pb-contaminated soils. These results support expanding the use of ZnONPs on other crops for safer and sustainable agriculture production in marginal soils.</p>