Chemical synthesis of nanoparticles is costly, harmful to the environment, and less efficient in terms of materials and energy demand. Therefore, the synthesis of ecologically friendly nanoparticles that do not produce harmful waste throughout the manufacturing process has piqued the curiosity of researchers. This can be accomplished by using biological synthesis procedures that are regarded as safe and environmentally friendly compared to traditional physical and chemical methods. Herein, tea (Camellia sinensis) leaf extract was used to synthesize the silver nanoparticles (AgNPs). Ultra-violet-visible spectrophotometry (UV-Vis), X-ray diffraction (XRD), Zeta potential, Fourier Transform Infrared (FTIR) spectroscopy, Field Emission Scanning Electron Microscopy (FESEM), and Energy Dispersive Spectroscopy (EDX) were used to characterize the as-synthesized AgNPs. The surface plasmon resonance (SPR) peak of AgNPs was observed at 400–500 nm in UV-Vis spectra. The band gap energy of 3.605 eV was computed by Tauc’s plot analysis, suggesting the semiconductor applications of AgNPs. The size of AgNPs estimated from FESEM was 66.87 ± 16.74 nm. EDX analysis confirmed the AgNPs’ purity with a strong silver signal at 3 keV. The evaluation of antimicrobial activity of AgNPs against Gram-negative bacterium (Escherichia coli), Gram-positive bacterium (Bacillus subtilis), and pathogenic fungus (Candida albicans) was carried out. The zone of inhibition (ZOI) exhibited against those microbes was respectively 12, 11, and 10 mm, against the 20 mm ZOI exhibited by the control kanamycin. These corroborating facts have led to the conclusion that Camellia sinensis leaf extract is suitable for the environmentally friendly synthesis of AgNPs with potential antimicrobial uses.