Micelles and micelle-forming amphiphilic polymers play an important role in nature and in everyday life. Today, the bio-inspired development of synthetic polymers with micelle-like molecular architectures goes well beyond the scope of biological micellar systems. Particularly, amphiphilic core–shell polymeric electrolytes, equivalent to unimolecular micelles, are much more robust and less sensitive to shear-, temperature-, and pH-induced disintegration. Among amphiphilic materials, polymeric ionic liquids (PILs) are attracting great attention, since they combine the features of low-molecular-weight ionic liquids (ILs) with the properties and facile processing typical of polymers. Hence, the precise incorporation of IL moieties into macromolecular core–shell and onion-like architectures represents an attractive route to nanostructured PILs exhibiting functions typical for micelles. This chapter highlights the progress made in bio-inspired molecular systems engineering by designing micelle-like PILs comprising dendritic and hyperbranched polymers as cores and IL-moieties with variable alkyl substitution in their periphery. Special focus is placed upon the design of hyperbranched PILs with onion-like topologies, enabling tailoring specific functions. The wide applications of compartmentalized PIL systems span from the synthesis of particles and dispersions to catalysis and smart materials that respond with property changes to external stimuli.