In bulk, when the different blocks are chemically immiscible, the balance between the entropically and enthalpically driven phase separation and the chemical bond constraints between the blocks drives the formation of ordered domains. In solution, the interactions between the solvent and the different blocks dictate the ability to form well-defined structures. The architecture, molecular weight, volume fractions of blocks, and chemical functionality can all be set in the synthesis, making designer block copolymers a reality. The ability to effectively design nanoparticles and nanostructures to your preference, coupled with the wide range of applications associated with them, have made them an incredibly popular topic of research. Herein, we explore the latest developments in block copolymer nanoparticles and nanostructures formed in solution. We also look into the applications lined up for them, both immediate and in the near future.