Deep eutectic solvents (DESs), considered green solvents, are built with natural compounds like amino acids, sugars, and carboxylic acids. They have great potential over conventional organic solvents and have a wide range of potential uses. DESs consist of cheap, pure components that bond together to produce a clear liquid due to an extensive hydrogen bonding network. DESs show certain physical and chemical traits, such as melting at a low temperature, having a lower tendency to evaporate, high resistance to heat, and the capability to solubilize many substances. Being considered nontoxic, biodegradable, and environmentally safe, DESs are drawing more attention from scientists in various disciplines right now. This chapter explains how DESs are used in biotechnology, such as in making enzymes stronger and more useful for applications like breaking down sugars and improving their performance in reactions. It also covers their role in extracting and cleaning up helpful materials from plants, microbes, and the sea; progress in regenerative medicine; new drug development; drug system improvements; and growth in bio-based transformations. This chapter describes these methods; their principal qualities, uses, benefits, and production techniques; and any difficulties faced in biotechnology and biology. As a result, it also identifies the ways the field of DESs has progressed and can lead to new breakthroughs in biotechnology.