Urban areas are increasingly experiencing the adverse effects of the “urban heat island” (UHI) phenomenon, driven by rapid urbanization, reduced green spaces, and the widespread use of heat-retaining materials. These factors exacerbate urban temperatures, increase energy demands, and contribute to environmental challenges. This paper explores recent advancements in mitigating UHI, focusing on bio-based solutions that offer a sustainable and innovative approach. Integrating bio-based materials, such as hempcrete, straw, and timber, into building construction and urban infrastructure can significantly reduce heat accumulation while enhancing thermal comfort and resilience to climate change. These materials not only lower urban temperatures but also contribute to reducing carbon emissions, improving energy efficiency in buildings, and fostering more sustainable urban environments. The study underscores the importance of bio-based materials as sustainable alternatives to conventional options, highlighting their potential for integration into urban planning to effectively address UHI, enhance energy performance, and support environmentally responsible urban development.