Addressing the imperative challenges in the field of chemistry involves the development of chemical processes that are environmentally friendly, economically viable, and sustainable. Green chemistry aims to reduce waste, achieve high rates of catalyst recovery, and achieve atomic efficiency in addition to the usual requirement for efficient and selective catalytic processes that will convert raw materials into valuable chemicals, medicines, and fuels. The fact that nanostructured materials satisfy the objectives of green chemistry makes them appealing candidates for use as heterogeneous catalysts in various organic reactions. A major global concern today is the presence of harmful environmental contaminants, both organic and inorganic, in water bodies. Introducing nanoparticles in water treatment processes allows for addressing challenges associated with conventional approaches while providing a more environmentally friendly and energy-efficient solution. Various types of nanomaterials are utilized for wastewater treatment, depending on the kind of contaminants and the required level of treatment efficiency. Novel and developing nanomaterials are being created as the area of nanomaterials advances. The long-term viability of these nanostructured catalysts together with their exceptional catalytic efficiency, positions them as essential contributors to the development of efficient and ecologically friendly water treatment methods. This chapter explores the trends and potential uses of green-synthesized nanocatalysts and nanomaterials for the sustainable removal of metal ions and pollutants from aqueous solutions as well as the health and environmental challenges associated with them. An overview of current advances on this contentious topic, in our opinion, could stimulate new thoughts and methods for creating low-cost, highly efficient nanostructured materials that lessen resistant pollutants for a sustainable environment.