This open access book brings together contributions on circular economy innovation, focusing on sustainability, waste management, circular design, and business models. Through case studies, technological advances, and conceptual frameworks, the book offers a broad, interdisciplinary overview of contemporary circular economy research and practice, with contributions that highlight wider applicability. Authors address practical, cross cutting themes: building reuse ecosystems, plastic waste management, lifecycle assessments and material innovation, circular practices in construction and fashion, recycling and wastewater treatment technologies, and policies and business models for circular startups aligned with the SDGs. Implementation strategies for SMEs, tourism and rural contexts, and sustainable crowdfunding initiatives are also covered. Designed to stimulate dialogue and speed adoption, this volume is a concise, actionable resource for academics, practitioners, policymakers, and industry leaders seeking solutions and best practices for implementing circular economy principles.