<p>The overwhelming global human population, rising food demand, and rapid growth of various industries have led to a significant increase in waste production. However, the excess waste poses a catastrophic threat to the ecosystem, impacting biodiversity, pollution levels, and human health. Such calamitous effects necessitate strategic implementation to utilise various types of potential waste materials. Hence, this review explores the emerging trends in the synthesis of waste-mediated nanoparticles from various waste materials, including kitchen waste, agricultural waste, animal waste, and algae waste, utilising a specific synthesis method for producing NPs that enable precise control over their characteristics. Given the critical role of phytochemicals in nanoparticle synthesis, this review incorporates a section that discusses the analytical techniques used for their identification. Finally, this review provides valuable insights into harnessing waste materials for synthesising NPs and their diverse applications, contributing to sustainable waste management practices, and addressing persistent environmental and health challenges.</p> Graphical Abstract <p></p>