Cellulosic ethanolCellulosic ethanol has emerged as a key component of next-generation biofuelsBiofuel, providing a sustainable alternative to fossil fuels while overcoming the limitationsLimitations of first-generation ethanol derived from food crops. Cellulosic ethanolCellulosic ethanol, which is made from lignocellulosic biomassLignocellulosic biomass such as agricultural residuesAgricultural residues, forestry byproducts, and dedicated energy crops, takes advantage of abundant non-edible feedstocks, reducing competition with food supply chains. This chapter examines the technological advances driving cellulosic ethanolCellulosic ethanol production, with a focus on pretreatmentPretreatments innovations, enzymatic hydrolysisEnzymatic hydrolysis, microbial fermentationMicrobial fermentation, and process integration. It highlights advances in consolidated bioprocessingConsolidated Bioprocessing (CBP), metabolic engineeringMetabolic engineering of robust microbes, and energy-efficientEfficient separation methods that improve yields while lowering costs. Despite these advances, commercializationCommercialization still faces significant challenges, such as high capital investment, enzyme costs, feedstock variability, and complex logistics. The chapter examines case studies of operational biorefineriesBiorefinery and the economic, environmental, and policyPolicies barriers that have slowed their widespread deployment. It also investigates strategic solutions for increasing competitiveness, such as biorefinery integration, lignin and co-product valorization, supportive policyPolicies frameworks, and circular bioeconomy approaches. This chapter emphasizes cellulosic ethanol'sCellulosic ethanol potential to significantly contribute to global decarbonization goals, energy security, and rural development by linking technological innovation with strategic planning.