Plant productivity is progressively threatened by several environmental stresses, both abiotic (such as drought, salinity, and temperature extremes) and biotic (including pathogens, pests, and weeds). These stressors interrupt physiological, biochemical, and molecular processes, reducing crop yield and quality. Nanotechnology offers a novel, sustainable solution for enhancing crop resilience and stress tolerance. Due to their small size, high surface area, and ability to penetrate cellular barriers, nanoparticles (NPs) such as silver, silicon, titanium, and selenium have shown potential and promise in controlling stress-responsive pathways in plants. This chapter outlines the types of stresses affecting crops and explores the applications of nanotechnology in agriculture, particularly through nanomaterials that improve tolerance to both abiotic and biotic challenges. It highlights the processes by which nanoparticles boost plant responses, including antioxidant defense enhancement, gene regulation, and improved nutrient uptake. Additionally, the role of nanomaterial-based sensors for real-time stress detection is reviewed as a tool for precision farming. However, despite the potential, challenges remain. Environmental hazards, nanoparticle toxicity, and the need for standardization in synthesis and application methods all need to be addressed. Biologically synthesized and green biodegradable nanoparticles develop as safer options that promote environmental compatibility. Future research integrating nanotechnology with omics and microbiology could lead to targeted, efficient, and sustainable stress management strategies that would start a new era of resilient agriculture.