This chapter elucidates various types of natural and synthetic emerging polymers and their application techniques in textile finishing processes. There are numerous polymers, such as polyaniline, polypyrrole, and so on, that have the potential to be applied in the multifunctional finishing of textiles. Along with the traditional techniques, emerging technologies like enzyme immobilization, plasma coating, nano-coating, layer-by-layer technologies, supercritical fluid coating, electroless metallization, and so forth for applying polymers as textile finishes are represented as well. Approaches of metal-based nanoparticle coatings have emerged to enrich the antimicrobial properties. Several studies have been conducted to endow textile finishes with eco-friendliness and health safety. For instance, efforts are being made to develop flexible alternatives for cross-linking agents containing formaldehyde contents. The chapter concludes with the functional finishes and their applications for enhancing functionality, safety, and aesthetics of textiles, together with future trends and technologies, practical instances, and the challenges regarding their uses.