This book provides a comprehensive review of the fundamentals and applications of multiporphyrin arrays ranging from basic spectroscopic features to a wide range of promising applications such as molecular wires, switches, sensors, artificial photosynthetic devices, and dye-sensitized solar cells based on a variety of multiporphyrin architectures using covalent and/or noncovalent molecular assemblies. Particularly, it focuses on energy and electron transfer processes occurring in multiporphyrin arrays in various environments such as single-molecule level, composite materials, LB films, and solid surface to provide better understanding of photofunctional molecular architectures.