Sustainable smart cities are at the forefront of urban development, aiming to balance economic prosperity with environmental sustainability. This review explores the critical role of Financial Technology (Fintech) in advancing environmental sustainability within smart city initiatives. Fintech innovations optimize resource management, enhance citizen engagement, and foster collaborative governance models, contributing to sustainable urban ecosystems. The evolution of sustainable smart cities highlights the transformative impact of technological advancements and Fintech solutions. From early urban planning concepts to the emergence of smart technologies in the 21st century, Fintech has accelerated this evolution, offering innovative financial services for green finance, renewable energy investment, and sustainable infrastructure development. Fintech platforms enable efficient resource allocation, transparent transactions, and citizen participation in sustainability initiatives. Integrating Fintech into urban development strategies unlocks opportunities for environmental sustainability while fostering economic growth and social equity. The convergence of sustainable smart cities and Fintech holds immense potential to address environmental challenges like climate change, pollution, and resource depletion. As cities embrace digital transformation and data-driven approaches, Fintech's role in promoting environmental sustainability becomes increasingly crucial. Fintech solutions include green financing platforms, smart energy management systems, digital payment solutions for sustainable transport, and blockchain for transparent environmental transactions. These tools enhance resource efficiency through data analytics, IoT integration, and AI-driven predictive maintenance. Fintech also improves citizen engagement through feedback mechanisms, crowdsourcing platforms, and digital education campaigns. However, challenges such as data privacy, the digital divide, and regulatory frameworks must be addressed to ensure successful implementation. Case studies like Singapore and Copenhagen demonstrate the effectiveness of Fintech in promoting environmental sustainability. Future directions include advanced energy management systems, smart mobility solutions, and collaborative efforts among stakeholders. Policymakers, city leaders, and industry stakeholders must collaborate to create enabling environments for Fintech-driven solutions. By leveraging innovation, fostering collaboration, and committing to sustainable development principles, cities can build greener, smarter, and more resilient urban environments. The future of sustainable smart cities lies in the innovative integration of Fintech to promote environmental sustainability and improve quality of life for all residents.Sustainable smart cities are at the forefront of urban development, aiming to balance economic prosperity with environmental sustainability. This review explores the critical role of Financial Technology (Fintech) in advancing environmental sustainability within smart city initiatives. Fintech innovations optimize resource management, enhance citizen engagement, and foster collaborative governance models, contributing to sustainable urban ecosystems. The evolution of sustainable smart cities highlights the transformative impact of technological advancements and Fintech solutions. From early urban planning concepts to the emergence of smart technologies in the 21st century, Fintech has accelerated this evolution, offering innovative financial services for green finance, renewable energy investment, and sustainable infrastructure development. Fintech platforms enable efficient resource allocation, transparent transactions, and citizen participation in sustainability initiatives. Integrating Fintech into urban development strategies unlocks opportunities for environmental sustainability while fostering economic growth and social equity. The convergence of sustainable smart cities and Fintech holds immense potential to address environmental challenges like climate change, pollution, and resource depletion. As cities embrace digital transformation and data-driven approaches, Fintech's role in promoting environmental sustainability becomes increasingly crucial. Fintech solutions include green financing platforms, smart energy management systems, digital payment solutions for sustainable transport, and blockchain for transparent environmental transactions. These tools enhance resource efficiency through data analytics, IoT integration, and AI-driven predictive maintenance. Fintech also improves citizen engagement through feedback mechanisms, crowdsourcing platforms, and digital education campaigns. However, challenges such as data privacy, the digital divide, and regulatory frameworks must be addressed to ensure successful implementation. Case studies like Singapore and Copenhagen demonstrate the effectiveness of Fintech in promoting environmental sustainability. Future directions include advanced energy management systems, smart mobility solutions, and collaborative efforts among stakeholders. Policymakers, city leaders, and industry stakeholders must collaborate to create enabling environments for Fintech-driven solutions. By leveraging innovation, fostering collaboration, and committing to sustainable development principles, cities can build greener, smarter, and more resilient urban environments. The future of sustainable smart cities lies in the innovative integration of Fintech to promote environmental sustainability and improve quality of life for all residents.