In this present study, we report a facile microwave assisted green synthesis of ZnO/Ag nanocomposites (denoted as G‐ZnO/Ag NCs) by employing Tridax procumbens leaf extract as a green solvent for photocatalytic, antimicrobial and cytotoxicity activities. The prepared nanocomposites was characterized by various techniques to study its crystallinity, morphology, structure, chemical composition, optical properties, and so on. The nanocomposites exhibited excellent photocatalytic performance (90.2 %) toward methylene blue degradation when irradiated under visible light (120 min). Furthermore, the G‐ZnO/Ag NCs showed good reusable properties up to four consecutive cycles. In addition, the resultant nanocomposites showed significant antimicrobial activity with the zones of inhibition of 9.85±0.12 and 10.51±0.63 mm against gram positive (Staphylococcus aureus) and 11.98±0.22 and 13.76±0.12 mm against gram‐negative (Escherichia coli), bacteria respectively, as measured using the well diffusion method. Although, the in‐vitro cytotoxicity test showed 39.58 % viability of MCF‐7 cells. In summary, this study suggest that G‐ZnO/Ag NCs as a promising tool for wastewater treatment and nano biomedical applications using low cost and eco‐friendly approach.