The development of sustainable and consistent methods for nanoparticle production is essential to the field of nanotechnology. Nanoparticles have been consistently evaluated and employed in various industrial applications during the past decade. Because of their many unique properties, such as UV filtering, photochemical activity, antifungal efficacy, catalytic capabilities, and antibacterial effects, zinc oxide nanoparticles (ZnO NPs) have attracted a lot of attention. Due to the elevated levels of harmful substances and the extreme conditions associated with chemical and physical techniques, eco-friendly approaches employing plants, fungi, bacteria, and algae have been implemented for nanoparticle synthesis. This study examines diverse sustainable production methods to demonstrate the importance of ZnO nanoparticles in numerous applications. Consequently, the study utilized multiple secondary sources to aggregate pertinent review papers. The findings show that compared to conventional physical and chemical synthesis methods, the green synthesis process is both much safer and more environmentally friendly. ZnO nanoparticles offer a viable substitute in water treatment technology and are efficient agents for wastewater treatment.