The review concerns recent progress in the design and synthesis of encapsulated nanomaterials based on Group VIII base metals useful for energy and environmental catalysis, including syngas conversion, CO2 dry reforming, steam reforming, methane conversion, and NH3 decomposition, as well as other nanocatalytic processes, for example, electrochemical synthesis. Catalysts with various encapsulated structures (core@shell, yolk@shell, core@tube, mesoporous, and layered structures) are described. The performance of encapsulated structures in catalytic reactions, including protection of metal nanoparticles from sintering which is favorable for activity preservation owing to the confinement effect and intensification of processes by multifunctional catalysts, is discussed. Prospects for application of encapsulated materials are analyzed.