Molybdenum nanoparticles (Mo NPs) have attracted significant attention in recent years for their potential to enhance plant stress resilience, offering an innovative approach to combat drought, salinity, and other abiotic and biotic stresses. Molybdenum (Mo) is an essential trace element that plays a crucial role in nitrogen fixation, enzyme activation, and various metabolic processes in plants. When prepared at the nanoscale, Mo NPs possess unique physical, chemical, and electrochemical properties, making them ideal candidates for a wide range of agricultural and biotechnological applications. Studies have shown that Mo NPs promote plant growth and productivity by modulating key biochemical activities, including nitrogen metabolism and antioxidant defenses. These nanoparticles enhance the activity of enzymes such as nitrate reductases and sulfite oxidases, which are vital for nutrient assimilation and stress tolerance. Additionally, Mo NPs reduce the production of reactive oxygen species (ROS), alleviating oxidative stress and improving overall crop health in challenging environments. Several sustainable green synthesis methods, such as plant- and fungal-based approaches, offer environmentally friendly ways to produce Mo NPs, broadening their application in agriculture. This chapter explores various synthesis techniques of Mo NPs, their mechanisms of action in plant systems, and their role in improving plant resilience to abiotic stresses such as drought, salinity, and extreme temperatures. Mo NPs also show promise in enhancing resistance to pathogens, presenting a biocompatible and effective strategy for disease management. The future of Mo NPs in agriculture will depend on understanding their biocompatibility, toxicity, and ecological impact. Integrating Mo NPs into agricultural practices offers a feasible pathway to increasing crop yields, sustainability, and food security amid climate change.