The pursuit of sustainable energy alternatives has intensified interest in green solvents for biofuel production. Deep eutectic solvents (DESs) have emerged as promising candidates for biomass processing due to their tunable physicochemical properties and environmentally benign nature. This chapter presents a comprehensive overview of DES applications in biofuel production pathways, including bioethanol, biodiesel, biogas, biohydrogen, and thermochemical biofuels. Interaction between DESs and lignocellulosic substrates obeys a wide range of mechanisms, which have been discussed in this chapter. These mechanisms potentially improve the substrate availability and enzymatic capacity. Additionally, thermochemical aspects of conversion are examined herein. The chapter focuses on the industrial applicability, techno-economics, solvent recovery and integration methods (for sustainable biorefinery) of generated biofuels. The case studies elucidate real-world examples of how DESs can significantly aid in considerable scientific advancements from the laboratory to the pilot/field programs. In summary, DESs encompass a promising approach toward advancing biofuel production in a commercial, energy-efficient manner.