With the rapid pace of urbanization reshaping cities worldwide, urban environments increasingly embody both dynamic opportunities and complex challenges related to environmental sustainability, climate change, and social equity. This introductory chapter offers a comprehensive overview of the contemporary urban complexities and explores the role of green urbanism in transforming cities into more resilient, inclusive, and sustainable environments. With a multidisciplinary approach, it highlights and expands on the integration of artificial intelligence (AI) and machine learning (ML) as emerging transformative tools for advancing sustainable urbanism approaches and practices, empowering cities to respond dynamically and equitably to evolving environmental and social demands. Regarding the volume, it compiles theoretical analyzes, synthesized evidence, international case studies, and practical applications to foster a shared understanding of green urbanism’s role in creating better designed urban ecosystems. Structured into four parts—addressing, respectively: (1) sustainable urban planning, (2) circular economy, (3) technological innovations, and (4) urban green spaces and biodiversity—it offers a multidimensional exploration of adaptive and resilient urban systems that align with the principles of green urbanism and beyond. By bridging theory and practice, it serves as both a valuable resource and an urgent call to action, inspiring readers across different fields to drive meaningful progress in the journey toward achieving the goals of sustainable cities worldwide. This volume is designed for a broad readership across multiple disciplines, aiming to inspire urban planners, practitioners, policymakers, researchers, and community leaders with actionable insights and forward-thinking strategies.