This chapter delves into the evolving field of plant nanotechnology, which integrates nanotechnology with plant sciences to tackle key challenges in agriculture, horticulture, and environmental sustainability. By leveraging nanomaterials (NMs), this field introduces innovative strategies to enhance crop yields, strengthen plant resistance to environmental and biological stressors, and facilitate precision agriculture. Technologies such as nanosensors enable real-time plant health monitoring, advanced nutrient delivery systems enhance bioavailability, and nanocarriers optimize pesticide application while minimizing ecological harm. These advancements have the potential to reshape agricultural practices, making them more efficient, sustainable, and conducive to global food security. Despite its promising applications, plant nanotechnology also raises concerns regarding the interactions between NMs and plant systems, potential toxicity, and environmental impact. Ensuring its safe and responsible use requires comprehensive research and risk assessment. This chapter provides an in-depth exploration of the applications, benefits, and challenges of plant nanotechnology, highlighting its transformative role in modern agriculture and its contribution to global sustainability initiatives.