Silver nanoparticles are nano-sized metallic particles widely used in various fields, including medicine, pharmaceutical, food, and agriculture. This study carried out the green synthesis of AgNPs using leaf extracts from Azadirachta indica (Neem) and Ficus religiosa (Peepal) plants. The silver nanoparticles were characterized using sophisticated instruments. UV-visible spectroscopy confirmed the formation of AgNPs, while FTIR identified biomolecules (amino and carboxyl groups) acting as stabilizing agents. SEM determined the size and morphology of AgNPs. Particle size analysis was conducted using DLS, and zeta potential measurements provided information on the size and charge of the silver nanoparticles. The AgNPs were tested for antibacterial efficacy against Gram-positive (S. aureus) and Gram-negative (E. coli) bacteria. Similarly, the AgNPs exhibited high fungicidal activity against the fungal strain A. niger. The free radical scavenging activities of nanoparticles were studied using DPPH and Hydrogen Peroxide in vitro assays. The antiviral activity of AgNPs was investigated against the Sesbania mosaic virus (SeMV), which infects Sesbania plants. The AgNPs exhibited excellent antiviral properties, decreasing the viral infection in Sesbania plants, indicating the antiviral efficacy of silver nanoparticles in the agricultural sector.