The rational design of nanostructures is critical for achieving high-performance materials. The close-packing behavior of inorganic ions and their less controllable nucleation process impede the precise nanostructural construction of inorganic ionic compounds. The discovery of inorganic ionic oligomers (stable molecular-scale inorganic ionic compounds) and their polymerization reaction enables the controllable arrangement of inorganic ions for diverse nanostructures. This perspective aims to introduce inorganic ionic oligomers and their currently identified advantages in the precise design of inorganic and organic-inorganic hybrid nanostructures, directing the development of advanced materials with applications across the mechanical, energy, environmental, and biomedical fields. The challenges and opportunities for the controllable polymerization of inorganic ionic oligomers are presented at the end of this perspective. We suggest that inorganic ionic oligomers and their polymerization reaction offer a promising strategy for the preparation of inorganic and organic-inorganic hybrid materials.