Abstract: Green synthesis of copper nanoparticles (CuNPs) using plant extracts has gained significant attention as an eco-friendly, cost-effective, and sustainable alternative to conventional chemical and physical methods. Among various plant sources, neem (Azadirachta indica) leaf extract is widely utilized due to its rich content of bioactive compounds such as flavonoids, terpenoids, and phenolic constituents, which act as both reducing and stabilizing agents during nanoparticle formation. This review focuses on the synthesis, characterization, and potential applications of CuNPs produced using neem leaf extract. The formation of nanoparticles is typically indicated by a visible color change and is further confirmed through characterization techniques such as UV–Visible spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR). These techniques provide insights into particle size, morphology, crystallinity, and surface chemistry. Green-synthesized CuNPs exhibit promising antimicrobial, catalytic, and antioxidant properties, making them suitable for applications in medicine, agriculture, and environmental remediation. Despite these advantages, challenges such as particle aggregation, stability, and scalability remain. Overall, neem-mediated synthesis of copper nanoparticles represents a promising approach toward the development of environmentally benign nanomaterials.