Diabetes is among the most common debilitating and non-transferable diseases on the planet. The idea of using nanoparticles as a drug to treat diabetes mellitus seems intriguing. The Ag nanoparticles (Ag NPs) were effectively produced utilizing Moringa olifera (family: Moringaceae) plant extract employing a simple, cheaper, faster, and environmentally friendly green synthesis process. The antidiabetic effect of the produced Ag NPs was also tested in vivo. In the presence of plant extract, silver nitrate was converted to silver ions (Ag). XRD, FTIR, UV, XPS, and HRTEM studies characterize the formed Ag NPs. Ag NPs that have been biosynthesized, crystal nature was confirmed through XRD analysis and confirmed by UV-visible spectroscopy. FT-IR spectra were used to verify the presence of various functional groups in the biomolecules, forming and stabilizing the nanoparticles. The size of the NPS was in the range of 20-40 nm determined by HRTEM. The induction of diabetes using STZ showed increased blood glucose, cholesterol, triglycerides, LDL, VLDL, massive loss in body weight. These changes were reversed following the treatment of diabetic rats for 28 days and showed significant inhibition (p < 0.001) at a dose range of 0.2 mg/kg leaf extract and 0.2 mg/kg Ag NPs compared with the extract-treated group. These obtained results suggested that plant-mediated Ag NPs have shown promising antidiabetic and anti-hyperlipidemic activity compared to the crude extract.