The nanomaterial coating trend is rapidly developing owing to their incredibly small size, high strength to weight ratio, improving functionality and exhibiting unique properties that would not be seen in bulk materials. Nanomaterial coatings have wide range of applications in aerospace and defense. Aircraft and military vehicles faces harsh environments. Nano coating significantly improve resistance to wear and tear, enhances durability and corrosion resistance. In addition, in defense and aerospace weight reduction is crucial. Hence, Nano coatings can provide the same level of protection as traditional, heavier coatings, allowing for light construction of vehicles and aircraft. This translates to better fuel efficiency for airplanes and increased maneuverability for military vehicles. This chapter provides an overview of coatings and their types, merits and demerits, focusing on current prospects and future trends along with aerospace and defense applications.