Hierarchical structures constituting carefully arranged metal NPs exhibit collective properties that have potential applications in ultrasensitive chemical and metal ion detection, light harvesting, photovoltaics, etc. Therefore, researchers have investigated various methods to assemble NPs extensively, especially of noble metals, into hybrid structures to obtain desired functionalities. Though intra-system assemblies were the early examples of composite nanomaterials, assembling pre-fabricated NPs of different size regime, or different metals have proved to be of greater utility in biosensing, multimodal imaging and advanced optical communication. Nanoclusters (NCs) are strictly monodisperse in size and precise in composition. Their surface ligands are capable of exhibiting rich chemical interactions, making them potential building blocks of hierarchical nanostructures. In this chapter, we discuss the co-assemblies of NCs with noble metal NPs producing precise nanocomposites, which show emerging physicochemical properties in some cases. © 2023 Elsevier Inc. All rights reserved.