Water scarcity and pollution have emerged as major global challenges, necessitating the development of novel strategies for effective and long-term water treatment. Though the availability of water is higher, a major amount of water is salty. This limits the availability of water for human consumption. Further available amount of water is getting contaminated due to various domestic or industrial pollutants. It makes the separation of pollutants and water treatment highly important. Nanotechnology has arisen as a promising option for revolutionizing water treatment techniques, because of its unique properties and capabilities at the nanoscale. This chapter analyzes nanotechnology’s revolutionary potential in tackling water treatment issues, highlighting its multiple uses such as nanoparticle adsorption, membrane filtration, and enhanced oxidation processes. Introducing nanomaterials into water treatment technology improves pollutant removal efficiency, reduces energy consumption, and positively impacts the environment. Furthermore, the chapter delves into the challenges and components of nanotechnology in water treatment, such as potential risks and regulatory concerns. The interaction of nanotechnology and water treatment research will pave the path for a more sustainable and accessible water supply, eventually improving public health and environmental well-being. This chapter further underlines the significance of ongoing research and collaboration in realizing nanotechnology’s full promise in addressing the worldwide water crisis.