The textile industry is a significant polluter, contributing to 10% of global emissions. Annually, over 100 million tons of textile waste are generated worldwide, and the linear model of make-use-waste is prevalent. Consequently, 85% of textile products end up in landfills or are incinerated. Natural fibers (e.g., cotton) and nondegradable synthetic fibers (e.g., polyester) are the main raw materials for textiles, with synthetic fibers accounting for over 60% of the share. Given the nonbiodegradability of synthetic fibers and the increasing textile landfilling, there is a pressing need to extend the end of life of textile products and adopt a circular economy approach. Natural fibers such as cotton, due to their cellulosic nature, present viable opportunities to transform textile waste into value-added biochemicals. Enzymatic hydrolysis offers a promising and sustainable conversion pathway for this purpose. Glucose, the main chemical resulting from the enzymatic hydrolysis of cellulosic materials such as cotton textile waste, serves as a crucial building block to produce biofuels and other value-added chemicals with potential worth of thousands of dollars per ton. This chapter comprises the fundamentals of enzymatic hydrolysis of textile wastes, pretreatments needed to overcome conversion challenges (e.g., the cellulosic structure itself, and the presence of dyes), processes for upcycling glucose into biofuels and other chemicals, and the recycling of synthetic fibers. Additionally, it explores the economic potential of utilizing textile waste as an advanced resource within the circular economy framework.