Robust three-dimensional structure, aromaticity, high chemical and thermal stability of polyhedral boron clusters make them promising candidates for use in materials science. Boron clusters have been used for the synthesis of luminescent materials, polymers, coordination polymers or metal-organic frameworks, dendrimers, liquid crystals, and nonlinear optical materials. Some of these clusters have been used as molecular building blocks in nanoscience. This review summarizes the applications of polyhedral boron clusters in materials science.