This article presents a comprehensive systematic review examining the synergistic interplay of artificial intelligence (AI), artificial intelligence of things (AIoT), and urban digital twin (UDT) in data-driven environmental planning for sustainable smart cities. The study addresses critical research questions regarding the theoretical and practical foundations of these technologies, their integration in urban planning, and the challenges associated with their implementation. The review analyzes 185 studies published between January 2019 and December 2023, focusing on how AI, AIoT, and UDT contribute to advancing environmental sustainability in urban environments. The study highlights the transformative potential of AI and AIoT in reshaping data-driven urban planning, enabling more efficient resource management, energy optimization, and environmental monitoring. UDT, as a dynamic virtual replica of a real city, plays a pivotal role in simulating urban systems, facilitating scenario analysis, and supporting decision-making processes. The integration of AI and AIoT with UDT enhances the capabilities of urban planning, enabling more accurate predictions, real-time monitoring, and adaptive strategies for sustainable development. Key findings include the importance of data-driven approaches in addressing complex environmental challenges, the necessity of interdisciplinary collaboration, and the need for robust frameworks to guide the implementation of these technologies. The study identifies challenges such as data privacy, technological integration, and the need for standardized practices. It also emphasizes the importance of stakeholder engagement, policy development, and the adoption of innovative technologies to achieve sustainable urban development. The research underscores the potential of AI, AIoT, and UDT to revolutionize urban planning by providing intelligent, adaptive, and data-driven solutions. However, it also highlights the need for careful navigation of technical, social, and environmental challenges to ensure the successful integration of these technologies into sustainable smart cities. The study serves as a comprehensive reference for researchers, policymakers, and urban planners, offering insights into the future of sustainable urban development and the role of emerging technologies in shaping resilient, environmentally conscious cities.This article presents a comprehensive systematic review examining the synergistic interplay of artificial intelligence (AI), artificial intelligence of things (AIoT), and urban digital twin (UDT) in data-driven environmental planning for sustainable smart cities. The study addresses critical research questions regarding the theoretical and practical foundations of these technologies, their integration in urban planning, and the challenges associated with their implementation. The review analyzes 185 studies published between January 2019 and December 2023, focusing on how AI, AIoT, and UDT contribute to advancing environmental sustainability in urban environments. The study highlights the transformative potential of AI and AIoT in reshaping data-driven urban planning, enabling more efficient resource management, energy optimization, and environmental monitoring. UDT, as a dynamic virtual replica of a real city, plays a pivotal role in simulating urban systems, facilitating scenario analysis, and supporting decision-making processes. The integration of AI and AIoT with UDT enhances the capabilities of urban planning, enabling more accurate predictions, real-time monitoring, and adaptive strategies for sustainable development. Key findings include the importance of data-driven approaches in addressing complex environmental challenges, the necessity of interdisciplinary collaboration, and the need for robust frameworks to guide the implementation of these technologies. The study identifies challenges such as data privacy, technological integration, and the need for standardized practices. It also emphasizes the importance of stakeholder engagement, policy development, and the adoption of innovative technologies to achieve sustainable urban development. The research underscores the potential of AI, AIoT, and UDT to revolutionize urban planning by providing intelligent, adaptive, and data-driven solutions. However, it also highlights the need for careful navigation of technical, social, and environmental challenges to ensure the successful integration of these technologies into sustainable smart cities. The study serves as a comprehensive reference for researchers, policymakers, and urban planners, offering insights into the future of sustainable urban development and the role of emerging technologies in shaping resilient, environmentally conscious cities.