Nanotechnology has emerged as a revolutionary field in textile engineering, facilitating the creation of high-performance textile materials with advanced functionalities, including self-cleaning, UV protection, antimicrobial properties, antistatic characteristics, soil and stain repellency, water resistance, and flame retardancy. This chapter commences with the categorization of nano-finishing methods in textiles, succeeded by an in-depth examination of application strategies utilizing nanoparticles and nanolayers. Subsequent sections of this chapter examine the synthesis and integration of particular nano-finishes: self-cleaning surfaces modeled after the lotus effect and nano photocatalysts; hydrophobic and waterproof coatings realized through surface energy reduction via nanostructuring; UV-protective treatments employing TiO2 and ZnO nanoparticles; resilient antimicrobial finishes derived from nano silver as well as copper nanoparticles; and flame-retardant properties conferred by engineered nano chemicals. The emergence of nano-finishing has transformed both traditional and technical textiles, creating new opportunities for multifunctional and advanced applications. These advances increasingly align with two objectives: improving material performance and fostering environmental sustainability. As the discipline advances, nanotechnology persistently redefines the limits of textile functionality and environmental stewardship.