This chapter contains sections titled: Introduction Ceramic/Metal Nanocomposites Nanocomposites by Mechanical Alloying Nanocomposites from Sol–Gel Synthesis Nanocomposites by Thermal Spray Synthesis Metal Matrix Nanocomposites Bulk Ceramic Nanocomposites for Desired Mechanical Properties Thin-Film Nanocomposites: Multilayer and Granular Films Nanocomposites for Hard Coatings Carbon Nanotube-Based Nanocomposites Functional Low-Dimensional Nanocomposites Encapsulated Composite Nanosystems Applications of Nanocomposite Wires Applications of Nanocomposite Particles Inorganic Nanocomposites for Optical Applications Inorganic Nanocomposites for Electrical Applications Nanoporous Structures and Membranes: Other Nanocomposites Nanocomposites for Magnetic Applications Particle-Dispersed Magnetic Nanocomposites Magnetic Multilayer Nanocomposites Nanocomposite Structures having Miscellaneous Properties Concluding Remarks on Metal/Ceramic Nanocomposites