This book offers a timely and comprehensive summary of the circular bioeconomy, a transformative model that integrates sustainability, innovation, and resource efficiency to address global environmental and socio-economic challenges. Through a multidisciplinary lens, it examines how biological resources, waste materials, and renewable feedstocks can be harnessed to create value-added products while minimizing environmental impact. Readers are introduced to cutting-edge applications in biomass valorization, renewable energy, waste-to-resource strategies, and the development of sustainable materials. The volume also highlights the role of emerging technologies and systems thinking in fostering low-carbon, circular solutions for industry and society. This book opens the door with ideas for those committed to advancing sustainable development and transitioning toward a bio-based, circular economy.