The textile industry is one of the largest contributors to industrial wastewater generation, with bleaching and printing processes producing highly polluted effluents containing dyes, chemicals, and other toxic substances. These effluents are a significant environmental concern due to their high chemical oxygen demand (COD), color, and potential toxicity to aquatic life and human health. Biological treatment methods offer an effective and sustainable solution for the management of these textile effluents, providing an alternative to conventional chemical and physical treatment processes. This chapter explores the various biological treatment techniques, including aerobic and anaerobic processes, biofilm-based systems, and advanced technologies such as phytoremediation, mycoremediation, and enzyme-based treatments. It discusses the mechanisms through which microorganisms degrade the pollutants, the challenges faced in treating textile effluents, such as high toxicity and variability in effluent composition, and the limitation of these methods. Furthermore, the chapter reviews recent advancements in the field, including the use of genetically engineered microorganisms and nano-biotechnology to enhance treatment efficiency. Through case studies, the chapter illustrates the successful implementation of biological treatment systems in the textile industry, highlighting their potential for reducing environmental impact and achieving regulatory compliance. Finally, it provides recommendations for integrating biological treatment approaches into sustainable wastewater management practices in the textile sector.