This book comprehensively explores the fascinating intersection of deep eutectic solvents (DES) and nanocellulose, focusing specifically on their extraction methods and textile applications. It delves into the revolutionary role of deep eutectic solvents in nanocellulose extraction. Deep eutectic solvents are a class of non-toxic, low-cost, and environmentally friendly solvents formed by combining hydrogen bond donors and acceptors. They possess unique properties that make them highly suitable for dissolving cellulose and facilitating nanocellulose extraction with enhanced efficiency and sustainability. The book begins by providing a thorough overview of nanocellulose, its types, properties, and potential applications in the textile industry. It then delves into the fundamentals of deep eutectic solvents, their composition, properties, and synthesis methods. The subsequent chapters focus on the extraction techniques and strategies employed to obtain nanocellulose using deep eutectic solvents, highlighting the advantages and challenges associated with each method. It also discusses the potential modifications and functionalizations of nanocellulose to enhance its compatibility with textile applications, such as surface grafting, blending, and composite formation. The last part of the book shifts its focus to the applications of deep eutectic solvents in the textile industries. It explores the textile materials fibers, yarns, fabrics, and modification and dyeing and highlights the resulting improvements in mechanical strength, moisture management, thermal insulation, and UV protection.