Conventional textile wet processing poses a significant obstacle to environmentally sustainable production due to its resource-intensive techniques and toxic chemical inputs. The finishing process produces the greatest quantity of wastewater and substantially contributes to pollution. The textile industry is reevaluating its technology and chemical applications to meet sustainability objectives, such as carbon neutrality, water conservation, and diminished ecological impact. The implementation of biomaterial-based and sustainable finishing techniques is a possible avenue for more responsible manufacturing practices. The incorporation of biotechnology into wet processing, especially via enzymatic methods such as bio-washing and bio-stoning, illustrates the principles of green chemistry. Biomaterials, such as biopolymers and plant-derived extracts, are being extensively investigated for their potential in functional textile finishing due to their natural origin, biodegradability, and compatibility with cellulosic fibers. The biosynthesis of nanomaterials utilizing plant extracts or microorganisms is increasingly popular due to its cost-effectiveness, diminished reliance on chemicals, and simplicity of execution. This chapter offers a thorough examination of sustainable textile finishing technologies, encompassing nanotechnology, plasma treatment, enzymatic processing, biopolymer applications, and the utilization of natural agents.