This edited volume offers a multidisciplinary exploration of the complex challenges and emerging opportunities shaping contemporary urban development. Drawing on the dual themes of Future Smart Cities and Urban Regeneration and Sustainability, the book brings together diverse perspectives on how cities can evolve into more adaptive, inclusive, and environmentally conscious urban environments. As urban areas face escalating pressures from climate change, resource depletion, ecological degradation, social inequality, and technological shifts, this volume responds by integrating ecological and technological approaches into a cohesive framework for sustainable urban futures. With a multidisciplinary lens, this introductory chapter to Sustainable and Smart Cities: Ecological Design, Technological Innovation, and Climate Resilience provides the conceptual foundations for the volume. It examines the intersections of ecological thinking and intelligence, technological advancements, climate adaptation and governance, and inclusive planning—emphasizing how these frameworks can work in tandem to address critical urban challenges. It also outlines the structure of the book, linking its four thematic parts to the broader discourse on sustainable and smart urban transformation. The volume is organized into four interrelated parts—(I) Urban Resilience; Regeneration, and Social Equity, (II) Sustainable Urban Design and Spatial Technologies; (III) Artificial Intelligence; Urban Automation, and Smart Mobility Systems; and (IV) Energy Systems, Environmental Monitoring, and Climate Governance. Together, they offer theoretical insights, synthesized evidence, empirical studies, case-based applications, and forward-looking strategies. Each part represents a critical dimension of the evolving discourse on sustainable and smart urbanism, demonstrating how digital and environmental technologies, ecological infrastructure, data-driven planning and management, and participatory design and decision-making can be integrated to tackle systemic urban challenges. This volume offers a timely and robust contribution to the global dialog on sustainable urban development by weaving together research from urban planning, urban management, engineering, architecture, environmental science, computer science, and technological areas. It serves as a valuable resource for urban planners, policymakers, researchers, practitioners, and community leaders committed to fostering holistic, equitable, and future-ready pathways for sustainable and smart cities worldwide—ultimately driving meaningful progress in shaping resilient, ecologically balanced, and technologically advanced urban environments.