The green synthesis of metal oxide nanoparticles (MONPs) using Azadirachta indica (neem) as a biogenic reducing and capping agent is discussed in this review. Neem eliminates the need for harmful chemicals and solvents that are typically used in standard synthesis procedures of MONPs. This review discusses the many ways, such as coprecipitation, hydrothermal, and microemulsion approaches, that neem leaf extract can be used to produce oxide NPs. This review focused on obtaining data from recent advances in synthesis, characterization and applications of biological synthesis techniques. The relative abundance of A. indica (neem) means this can be widely used for creating reductant and stabilizing agents needed for MONPs formation. Using plant biomolecules in MONPs increases their toxicity toward microorganisms, enabling them to resist degradation and prevent ecological pollution. The review explores the size, shape, and crystal structure of neem-based NPs, which have potential uses in areas including water purification, biological imaging, and catalysis. Overall, this review finds that A. indica is a promising substitute for conventional synthetic techniques in the green synthesis of metallic oxide NPs.