In recognition of their superior capabilities, nanocoatings are increasingly widely used in multiple industries as coating technology advances. Surface hardness, adhesive strength, long-term and/or high-temperature corrosion resistance, the improvement of tribological real estate, and many other benefits are provided by coatings. Moreover, coatings can be placed in thinner and smoother thicknesses, allowing for greater customisation for machinery, increased efficiency, reduced fuel consumption, reduced environmental impact, and cheaper costs for upkeep and operation. Effective use of coatings lessens the impact of harsh conditions. A coating is a material consisting of layers with dimensions not larger than a few nanometers in size or containing components at the microscopic level. Good adhesion and excellent physical coverage of the coated surface are made possible by the minute diameters of the nanomaterials and the high density of their underlying boundaries. However, these exquisite qualities could provide active locations for corrosion assault. The corrosion resistance of ceramic, metallic, non-metallic, and nanocomposite coatings over metallic substrate surfaces is reviewed in this chapter. It lists the elements influencing these substrates’ corrosion and the circumstances in which these coatings were necessary to offer the required resistance.