This review article explores the emerging role of nanoparticles in enhancing nitrogen fixation in leguminous crops, a critical process for sustainable agriculture. Focusing on metal-based nanoparticles like iron oxide (Fe₂O₃) and zinc oxide (ZnO), as well as carbon-based nanoparticles such as carbon nanotubes (CNTs), the review discusses their effects on nitrogenase enzyme activity, root nodule formation, and nutrient uptake. Empirical studies demonstrate significant improvements in nitrogenase efficiency, nodule count, and nitrogen uptake in crops like soybean, chickpea, and peanut when treated with these nanoparticles. However, the potential risks of nanoparticle bioaccumulation, toxicity at higher concentrations, and environmental impacts are also highlighted, emphasizing the need for biodegradable nanoparticle development and regulatory guidelines. The review concludes that while nanoparticle-mediated nitrogen fixation holds promise for improving crop yields and reducing reliance on synthetic fertilizers, careful management and future research are crucial to ensuring the safe and effective integration of nanotechnology into agriculture.