This chapter underscores the pivotal role of nanocomposites and nanomaterials in the key stages of bioethanol production. They span from biomass fermentation to distillation and separation. In this context, nanomaterial technologies have demonstrated significant potential to enhance efficiency and bolster the sustainability of processes. For instance, the utilization of nanosensors for process monitoring and the analysis of environmental and sustainability considerations provide a broader outlook on the use of nanocomposites in bioethanol. The deployment of catalytic nanoparticles can notably enhance the efficiency of this process. Metallic nanoparticles, such as gold and silver, can serve as catalysts and expedite chemical reactions, enabling the more efficient breakdown of complex sugars found in biomass. Furthermore, when introduced, nanoparticles containing catalytic enzymes can increase the conversion of cellulose to glucose, increasing the bioethanol yield. However, using nanocomposites and nanomaterials in bioethanol production raises crucial environmental and sustainability issues. Although these technologies can increase efficiency and reduce costs, it is essential to consider the environmental impact of nanoparticle production and disposal. Sustainable methods of producing nanomaterials and recycling nanocomposites at the end of their useful life are vital to ensure a sustainable approach to bioethanol production.