Book excerpt: Noble metal-based nanocomposites are attractive for a rich variety of electrocatalytic applications as they can exhibit not only a combination of the properties associated with each component but also synergy due to a strong coupling between different constituents. Using noble metal as the base component, a plenty of methods have been recently demonstrated for the synthesis of noble metal-based nanocomposites with novel structures (e.g., alloys, core-shell, skin and 1D/2D structures). In this chapter, an account of recent advances of synthetic approaches to noble metal-based nanocomposites with controlled structures, compositions and sizes are reviewed. The relationship between structures and electrochemical properties of these nanocomposites in fuel cell field is discussed. The potential future directions of research in the field are also addressed.