The conventional sources of energy are depleting continuously with increasing the world population. Industrialization during the modern times results in an increment in energy demand. By substituting fossil fuels with green fuels, we can preserve more energy and improve the environment. There are various replacements for fossil fuels in order to fulfill energy requirements without harming nature: Biodiesel, Biobutanol, Bioethanol, Biohydrogen, Biogas, and Biochar. The employing of renewable energy technology is very suitable and sustainable. Various renewable substrates such as industrial waste, agricultural residue, municipal waste, dairy waste, etc. are present in abounded, and there is a requirement for waste management. Hence these waste streams could be utilized for energy production. Depending on substrate availability and the type of fuel, it is needed for different conversion technologies for biofuel production. Major techniques that are being used nowadays for the purpose of obtaining biofuels include hydrolysis, fermentation, saccharification, pyrolysis, gasification, torrefaction, transesterification, anaerobic digestion, etc. With the goal of handling global energy issues, scientific research and development have recently concentrated on developing new technologies. Hence, this chapter addresses the requirement of biofuels, renewable resource, technologies involved, and sustainable development of on green and circular economy.