Nanoparticles have emerged as a transformative innovation in plant science, offering novel strategies to enhance plant physiological performance and promote sustainable agricultural practices. This study examines the application of various nanoparticles, including metallic, carbon-based, and polymeric forms, and their impacts on key physiological processes such as germination, photosynthesis, nutrient uptake, enzymatic activity, and stress tolerance in plants. Through an integrated review of recent experimental and field-based studies, the research highlights that nanoparticle treatment significantly improves chlorophyll synthesis, root and shoot development, and overall crop productivity while enhancing tolerance to abiotic stresses such as drought, salinity, and heavy metal toxicity. The findings suggest that nanoparticles function as efficient nano-carriers for targeted nutrient delivery and act as regulators of plant metabolic and antioxidant systems. However, concerns regarding phytotoxicity, environmental accumulation, and long-term ecological effects remain critical challenges. The study concludes that while nanoparticle-based agricultural interventions hold strong potential for improving sustainable crop production systems, their application must be carefully regulated to ensure environmental safety and agronomic effectiveness.