This review article discusses the green synthesis of zinc oxide (ZnO) nanoparticles using biological sources such as plants, microbes, algae, and fungi. ZnO nanoparticles have various applications including antibacterial, antifungal, and antioxidant properties. Traditional methods for nanoparticle synthesis involve toxic chemicals and harsh conditions, making them less environmentally friendly. In contrast, green synthesis methods using biological sources are more eco-friendly, cost-effective, and produce nanoparticles with high stability and purity. The article highlights the use of plant extracts, such as those from Aloe Vera, Trifolium pratense, and Azadirachta indica, for the synthesis of ZnO nanoparticles. These methods involve the reduction and stabilization of metal ions by phytochemicals present in the plant extracts. The synthesized nanoparticles are characterized using techniques like XRD, FTIR, SEM, and TEM. The study also discusses the use of bacteria, such as B. licheniformis and Rhodococcus pyridinivorans, for the biosynthesis of ZnO nanoparticles, which exhibit photocatalytic activity and antibacterial properties. Microalgae and macroalgae, such as Sargassum muticum and Sargassum myriocystum, are also used for the synthesis of ZnO nanoparticles. These methods are efficient and produce nanoparticles with varied shapes and sizes. Fungi, including Aspergillus fumigatus and Candida albicans, are used for the synthesis of ZnO nanoparticles, which are stable and have various applications in biomedical and industrial fields. The review emphasizes the advantages of green synthesis methods over traditional methods, including reduced environmental impact, lower cost, and the ability to produce nanoparticles with desired properties. The study also discusses the potential applications of ZnO nanoparticles in various fields, including medicine, cosmetics, and environmental remediation. Overall, the review highlights the importance of green synthesis methods in the development of sustainable and eco-friendly nanoparticle technologies.This review article discusses the green synthesis of zinc oxide (ZnO) nanoparticles using biological sources such as plants, microbes, algae, and fungi. ZnO nanoparticles have various applications including antibacterial, antifungal, and antioxidant properties. Traditional methods for nanoparticle synthesis involve toxic chemicals and harsh conditions, making them less environmentally friendly. In contrast, green synthesis methods using biological sources are more eco-friendly, cost-effective, and produce nanoparticles with high stability and purity. The article highlights the use of plant extracts, such as those from Aloe Vera, Trifolium pratense, and Azadirachta indica, for the synthesis of ZnO nanoparticles. These methods involve the reduction and stabilization of metal ions by phytochemicals present in the plant extracts. The synthesized nanoparticles are characterized using techniques like XRD, FTIR, SEM, and TEM. The study also discusses the use of bacteria, such as B. licheniformis and Rhodococcus pyridinivorans, for the biosynthesis of ZnO nanoparticles, which exhibit photocatalytic activity and antibacterial properties. Microalgae and macroalgae, such as Sargassum muticum and Sargassum myriocystum, are also used for the synthesis of ZnO nanoparticles. These methods are efficient and produce nanoparticles with varied shapes and sizes. Fungi, including Aspergillus fumigatus and Candida albicans, are used for the synthesis of ZnO nanoparticles, which are stable and have various applications in biomedical and industrial fields. The review emphasizes the advantages of green synthesis methods over traditional methods, including reduced environmental impact, lower cost, and the ability to produce nanoparticles with desired properties. The study also discusses the potential applications of ZnO nanoparticles in various fields, including medicine, cosmetics, and environmental remediation. Overall, the review highlights the importance of green synthesis methods in the development of sustainable and eco-friendly nanoparticle technologies.