Integrating optical fibers into textiles opens up a wide range of new, fascinating applications – starting from data transmission to sensory abilities, new lightening concepts, and advanced medical therapies. This chapter gives first an overview on the working principle and light transmission mechanisms in optical fibers. It discusses different types of optical fiber materials, before it summarizes recent developments in processing these materials into textile structures. Finally different application fields are explored, which leads to highlighting future trends and potentials of optical fibers.