The rapid advancement of thermal management technologies has increased the demand for efficient heat transferfluids.Conventional fluids such as water, ethylene glycol, and oil often exhibit low thermal conductivity, limiting their performanceinhigh-heat-flux systems. Nan fluids—engineered colloidal suspensions of nanoparticles (typically metal, metal oxide, or carbon-basedmaterials)in base fluids—have emerged as a promising solution to overcome this limitation. This paper reviews the role of nanofluids inenhancingconvective heat transfer performance in various applications, including cooling systems, heat exchangers, and electronicdevices.Keyparameters such as nanoparticle type, size, volume concentration, and flow conditions are analyzed for their influenceonthermalconductivity, viscosity, and overall heat transfer coefficient. Experimental findings and numerical studies consistentlydemonstratesignificant improvements in convective heat transfer rates, although stability and pumping power remain important challenges. Thestudyconcludes that optimized nanofluid formulations offer substantial potential for future thermal systems, particularly in energy, automotive,and microchannel cooling applications. Keywords: Nanofluids, Convective heat transfer, Thermal conductivity, Viscosity, Stability, Energy systems, Micro channel cooling