Nanotechnology-enhanced fiber-reinforced polymer composites have shown significant advancements in processing techniques and applications. This review discusses the use of nanoparticles, nanofibers, and nano-coatings to improve the mechanical properties, surface modification, and functionality of fiber-reinforced polymer (FRP) composites. The paper highlights the potential benefits of nanotechnology in enhancing the performance of composites, including improved mechanical properties, surface modification, and sensing capabilities. It also examines the challenges associated with incorporating nanotechnology into composites and provides recommendations for future research. Nanoparticles, such as carbon-based, metal-based, and metal oxide nanoparticles, are used as reinforcements to enhance the mechanical, thermal, and electrical properties of composites. Carbon-based nanoparticles, including carbon nanotubes and graphene, are particularly effective in improving the mechanical properties of composites. Metal-based nanoparticles, such as silver and titanium dioxide, are also used to enhance the properties of composites. Metal oxide nanoparticles, such as aluminum oxide and silicon dioxide, are used to improve the mechanical and thermal properties of composites. Nanofibers, including carbon nanofibers, graphite nanofibers, polyamide nanofibers, ceramic nanofibers, aramid nanofibers, and cellulose nanofibers, are used as reinforcements to enhance the mechanical properties of composites. These nanofibers have a high aspect ratio and can be tailored for specific applications. The fabrication of nanofibers can be achieved through various methods, including electrospinning, self-assembly, phase separation, chemical vapor deposition, and plasma-enhanced chemical vapor deposition. Nano-coatings are used to modify the surface properties of FRP composites, such as scratch resistance, wear resistance, adhesion, and hydrophobicity. Silica nanocoatings are particularly effective in improving the surface properties of FRP composites. The use of nanotechnology in composites has the potential to significantly enhance the performance of composites in various industries, including aerospace, automotive, defense, and biomedical applications. However, challenges remain in the incorporation of nanotechnology into composites, and further research is needed to fully realize the potential of nanotechnology in composites.Nanotechnology-enhanced fiber-reinforced polymer composites have shown significant advancements in processing techniques and applications. This review discusses the use of nanoparticles, nanofibers, and nano-coatings to improve the mechanical properties, surface modification, and functionality of fiber-reinforced polymer (FRP) composites. The paper highlights the potential benefits of nanotechnology in enhancing the performance of composites, including improved mechanical properties, surface modification, and sensing capabilities. It also examines the challenges associated with incorporating nanotechnology into composites and provides recommendations for future research. Nanoparticles, such as carbon-based, metal-based, and metal oxide nanoparticles, are used as reinforcements to enhance the mechanical, thermal, and electrical properties of composites. Carbon-based nanoparticles, including carbon nanotubes and graphene, are particularly effective in improving the mechanical properties of composites. Metal-based nanoparticles, such as silver and titanium dioxide, are also used to enhance the properties of composites. Metal oxide nanoparticles, such as aluminum oxide and silicon dioxide, are used to improve the mechanical and thermal properties of composites. Nanofibers, including carbon nanofibers, graphite nanofibers, polyamide nanofibers, ceramic nanofibers, aramid nanofibers, and cellulose nanofibers, are used as reinforcements to enhance the mechanical properties of composites. These nanofibers have a high aspect ratio and can be tailored for specific applications. The fabrication of nanofibers can be achieved through various methods, including electrospinning, self-assembly, phase separation, chemical vapor deposition, and plasma-enhanced chemical vapor deposition. Nano-coatings are used to modify the surface properties of FRP composites, such as scratch resistance, wear resistance, adhesion, and hydrophobicity. Silica nanocoatings are particularly effective in improving the surface properties of FRP composites. The use of nanotechnology in composites has the potential to significantly enhance the performance of composites in various industries, including aerospace, automotive, defense, and biomedical applications. However, challenges remain in the incorporation of nanotechnology into composites, and further research is needed to fully realize the potential of nanotechnology in composites.