Green nanotechnology is now well established, showcasing how natural precursors can replace hazardous synthesis routes. This review analyzes the diverse biotechnological applications of biogenic nanomaterials. In the biomedical field, they have demonstrated significant efficacy as antimicrobial agents, targeted drug delivery vehicles, wound healers, and theragnostic platforms. They also enhance food packaging security, optimize nano-fertilizers, and control insect pests. Additionally, their unique surface properties and catalytic activity make them key candidates for pollutant remediation and advanced chemical sensors. Ultimately, while green nanoparticles offer clear advantages over traditional chemical methods, key bottlenecks, like batch-to-batch reproducibility, industrial scalability, and long-term ecotoxicological and multigenerational impacts, still need to be addressed.