This chapter overviews the cellulose-degrading enzymes produced by microorganisms and their utility in the textile industry. The cellulose-degrading enzyme system is composed of cellobiohydrolases I and II (EC 3.2.1.76 and EC 3.2.1.91), endo-1,4-β-glucanase (EC 3.2.1.4), and β-glucosidase (EC 3.2.1.21), acting in synergy for the conversion of cellulose into glucose. In addition, recently discovered enzymes, such as CBM33 and GH61, were found to increase the efficiency of cellulose breakdown by acting on its surface. The use of cellulases in the textile industry has proven to be an important tool to make textile processing environmentally friendly and to reduce energy demand and water consumption. Their applications in the textile industry include bioscouring, biopolishing, and biostonewashing.