Elasticity is the ability of a material to be stretched under tensile load and to return to its original starting position on recovery. It is one of the most important properties of textiles and has a direct effect on their functionality. It is elasticity that makes it possible to open up different areas of application through special and mass-produced products, especially in the areas of stretch and compression. About 80% of all clothing textiles produced today, as well as almost all medical textiles, contain special elastic yarns that enable or reinforce elasticity.This edited work describes and explains the production of elastic textiles from raw material to fiber and yarn, processing, and application. Environmental aspects (e.g. recycling) are also explained. Expert contributions from industry and research present the state of the art and practical new developments in such a way that users from industry and trade can use them in line with market requirements. In addition, trainees and students as well as textile experts are addressed.