This study aimed to develop a green and safe method for producing silver nanoparticles (AgNPs) using the root extract of Withania somnifera (WS) and evaluate their antioxidant properties. UV-visible spectroscopy revealed a maximum absorption peak at 430 nm. Fourier-transformed infrared spectroscopy confirmed the presence of phenolic coatings on Ws-AgNPs, indicating their role in stabilizing and reducing Ag ions into Ws-AgNPs. Scanning electron microscopy analysis demonstrated that Ws-AgNPs had a spherical shape and a size range of 74–88 nm. Energy dispersive X-ray spectroscopy analysis confirmed silver as the primary element in Ws-AgNPs. X-ray powder diffraction analysis indicated a face-centered cubic crystalline structure for Ws-AgNPs. The potential antioxidant activities of Ws-AgNPs were evaluated using various scavenging assays. At the highest concentration tested (500 µg/mL), 95 ± 1.3%, 98 ± 1.6%, 76.9 ± 1.44%, and 89.6 ± 1.6% scavenging activities were observed with 2,2-diphenyl-1-picrylhydrazyl, 2,2′-azinobis-3-ethylbenzothiazoline-6-sulfonic acid, phosphomolybdate, and H2O2, respectively. Moreover, the reducing power of Ws-AgNPs was higher than that of the methanolic WS root extract and showed a concentration-dependent trend. In conclusion, the green-synthesized Ws-AgNPs from W. somnifera showed remarkable antioxidant activity, as evidenced by their low IC50 values. Due to these findings, it is suggested that Ws-AgNPs have the potential to be used as potent antioxidant agents in the cosmetic, food, and pharmaceutical industries.