This article provides an overview of a variety of applications of 29Si NMR to materials, with an emphasis on solid-state 29Si NMR of siloxane polymers, silicates, functionalized silica, porous materials, zeolites, and glasses. The unique features of the 29Si isotope with respect to NMR spectroscopy and an overview of the 29Si chemical shift ranges of various structural environments in silicon-containing compounds and materials (in both solution and in solids) are presented. The main techniques of solid-state 29Si NMR spectroscopy are briefly described, including a number of important advanced two-dimensional correlation techniques. A range of applications of 29Si NMR to siloxanes, silicates, functionalized silica, zeolites, and glasses are described. Finally, recent developments in dynamic nuclear polarization techniques that have led to remarkable increases in sensitivity and have enabled the application of 29Si NMR to new materials and new aspects of materials are outlined.