Marine biofouling poses a significant threat to maritime industries. This chapter reviews the development of nanocomposite antifouling coatings as environmentally responsible alternatives to traditional toxic solutions. It examines various mechanisms, including low surface energy, superhydrophobicity, controlled biocide release, and photocatalysis. The analysis highlights that incorporating nanomaterials enhances mechanical properties and fouling resistance. A key finding is the superior performance of multi-factor synergistic coatings, which combine several antifouling strategies for broad-spectrum, long-lasting efficacy. However, challenges such as nanoparticle dispersion stability and long-term durability in marine environments must be resolved to enable widespread commercial application. Nanocomposite coatings represent a promising, green direction for future antifouling technology.