We investigate the functions of many types of nanomaterials in enhancing pretreatment, catalytic conversion, and fuel upgrading. These include carbon-based nanostructures, metal oxide and metal nanoparticles, and mesoporous catalysts. Transesterification, pyrolysis, and gasification are three critical processes that make extensive use of nanocatalysts. In order to increase the yield and selectivity of biochemical conversions, this chapter also covers the breakthroughs in nanotechnology for biomass to biofuels conversion, which includes enzyme immobilization and nanotechnological systems. In addition, it examines the scalability of these technologies, the environmental and economic implications, the recyclability and recovery of nanomaterials, and the life cycle consequences. Promising new avenues for investigation include eco-friendly nanomaterial production, biorefinery integration, and machine learning applied to catalyst design. This chapter shows how nanotechnology might increase the efficiency of biomass conversion via case studies and new experimental data, providing a technique to make biofuels that are both sustainable and competitive in the market.