Deep eutectic solvents (DESs) have revealed themselves as a transformative form of green solvents. Due to their remarkable properties, environmental compatibility, and wide-ranging applicability, they are excellent alternatives to conventional solvents. The chapter primarily explores the multifaceted applications of DESs in advanced material engineering, highlighting their role as green electrolytes, solvents, and functional media. DESs have demonstrated extraordinary utility in metal electrodeposition, promoting uniform and high-quality coatings of alloys and metals. Studies have shown that metal deposited in the presence of DESs possesses smoother and brighter surfaces compared to traditional aqueous systems. Besides electrodeposition, metal recycling could also be aided by DESs, owing to their dissolving properties. Examples of metal recycling were discussed based on recently published research work. We particularly emphasized the dissolution of valuable elements from discarded lithium-ion batteries. Another noteworthy function of DESs is the synthesis of nanomaterials. The section of the chapter emphasizes the DES’s assistance in forming nanoparticles with custom sizes, shapes, and crystalline properties. Lastly, we elaborated on the impact of DES on polymer chemistry, where DESs enabled controlled radical polymerizations, such as RAFT, and self-healing polymer electrolytes for batteries were discussed in detail. The chapter delves into the DESs as a potentially viable platform for sustainable innovation in electrochemistry, nanotechnology, and materials science.