The present study focuses on the green synthesis of zinc oxide (ZnO) and iron oxide (FeO) nanoparticles using Tribulus terrestris leaf extract and the evaluation of their antibacterial potential against selected pathogenic bacteria. The biosynthesized nanoparticles were characterized using FTIR, FESEM, zeta potential, and XRD analyses. FTIR results confirmed the involvement of phytochemicals such as phenolics, flavonoids, and proteins in the reduction and stabilization of nanoparticles. FESEM analysis revealed irregular, agglomerated nanostructures with rough surface morphology, while zeta potential measurements indicated good colloidal stability due to negatively charged surfaces. XRD patterns confirmed the crystalline nature and phase purity of the nanoparticles, with ZnONPs exhibiting a hexagonal wurtzite structure. The antibacterial activity was assessed against Escherichia coli, Staphylococcus aureus, Bacillus subtilis, and Pseudomonas aeruginosa using different concentrations (25–100 µg/ml). The results demonstrated a concentration-dependent increase in antibacterial activity, with nanoparticles showing significantly higher efficacy compared to plant extract. Among the tested samples, ZnONPs and FeONPs exhibited notable inhibitory effects, attributed to their nanoscale size, enhanced surface reactivity, and ability to generate reactive oxygen species. The findings suggest that Tribulus terrestris-mediated nanoparticles hold promising potential as effective antimicrobial agents for biomedical and environmental applications.