Silver nanoparticles (AgNPs) exhibit distinctive electrical, optical, and thermal properties enabling diverse applications, but their utility is limited by their tendency to aggregate. Pomelo peel extract (PPE), rich in flavonoids and ascorbic acid, was utilized as a dual reducing and stabilizing agent for the rapid green synthesis of AgNPs. The synthesis, optimized by a one-variable-at-a-time approach, yielded colloidal AgNPs with a characteristic surface plasmon resonance peak at 403 nm. Transmission electron microscopy confirmed predominantly spherical, uniformly dispersed nanoparticles with an average size of 23.04 ± 1.01 nm, corroborated by dynamic light scattering (DLS) analysis (18.6 nm). X-ray diffraction (XRD) patterns revealed a face-centered cubic crystalline structure, while zeta potential measurements (−27.1 mV) confirmed long-term colloidal stability. The biosynthesized AgNPs demonstrated robust antibacterial activity, with inhibition zones of 14.51 ± 0.58 for E. coli and 11.78 ± 0.51 mm for S. aureus. Minimum inhibitory concentrations (MICs) were 36 for E. coli and 73 μL/mL for S. aureus, with corresponding bactericidal thresholds of 73 and 146 μL/mL, respectively. These findings highlight PPE-mediated AgNPs as an eco-friendly platform for antimicrobial and environmental applications.