The increasing demand for food production, coupled with the growing threat of water scarcity and climate variability, has necessitated the development of innovative water management strategies in agriculture. This chapter explores the integration of nanotechnology into precision agriculture as a transformative approach to achieving sustainable water management. It begins by examining the global challenges posed by inefficient irrigation practices and freshwater depletion, particularly in arid and semiarid regions. The chapter outlines how precision agriculture—through technologies like GPS, remote sensing, and data analytics—can optimize water use, and how nanotechnology complements these efforts by offering advanced materials and devices with enhanced functionality. Nanomaterials such as nanoclays, nanohydrogels, carbon nanotubes, graphene oxide, and metal oxides are shown to improve soil water retention, enable controlled release of water and nutrients, and purify irrigation sources by removing contaminants. Furthermore, nano-enabled sensors are revolutionizing real-time monitoring of soil moisture, salinity, and plant water status, facilitating data-driven irrigation decisions. The chapter also introduces smart nano-irrigation systems and the integration of AI and the Internet of Nano-Things (IoNT), highlighting their role in automating water delivery and optimizing resource use across diverse field conditions. Environmental safety and long-term implications of using nanomaterials are also addressed, with an emphasis on developing biodegradable and eco-friendly alternatives. Policy considerations, commercialization pathways, and strategies for farmer adoption are discussed to support the practical deployment of nano-enabled technologies. The chapter concludes by emphasizing the strategic importance of nanotechnology in enhancing water use efficiency, supporting climate-resilient agriculture, and ensuring sustainable food systems.