Neem, belonging to the Mahogany family (Meliaceae), is esteemed for its medicinal properties and has long been utilized in Ayurvedic medicine. The neem tree is available as a sustainable source of bioactive compounds that can function as both stabilizing and reducing agents in the synthesis of metal oxide nanoparticles. Among all metal oxides, zinc oxide (ZnO) nanoparticles, owing to their tunable band gaps and surface chemistries, are most commercialized for various applications, including antibacterial, photocatalytic, and supercapacitor devices. However, the scope of improvement lies in their sustainable production through green technologies, such as using neem-based extracts as precursors. This chapter discusses the green synthesis method of zinc oxide (ZnO) nanoparticles using aqueous extracts derived from several parts of the neem plant (Azadirachta indica). Preparing extract of neem leaf, a defining step in the synthesis is described in detail, emphasizing its significance in the synthesis process. Furthermore, this review elucidates the diverse applications of ZnO nanoparticles obtained using neem extracts, highlighting their potential in various sectors. This chapter also highlights the importance of green-synthesized ZnO nanoparticles over conventionally prepared counterparts. Green synthesized ZnO nanoparticles, which utilize natural extracts and eco-friendly processes, offer several advantages over chemical synthesized ZnO, including reduced environmental impact, avoidance of hazardous chemicals, lesser toxicity, and enhanced biocompatibility. Moreover, the utilization of various neem parts including bark, leaf, gum, essential oil, fruit, and seed provides a renewable and eco-friendly avenue for scalable and sustainable biogenic ZnO fabrication. Through a deep-dive exploration, this review underscores the significance of neem-based ZnO nanoparticles as eco-friendly materials with versatile applications, emphasizing the crucial role of green synthesis in advancing nanotechnology.