Smart cities, that employ innovative technologies to enhance environmental sustainability, maximize resource management, and raise living standards, have grown because of rapid urbanization and the growing desire for sustainable living. The Internet of Things (IoT) and blockchain come together to offer revolutionary convenience for running smart cities and accomplishing sustainability objectives. Blockchain facilitates efficient data exchange, data security, stakeholder trust, and the establishment of decentralized organizations to enhance decision-making by examining key domains such as healthcare, energy distribution, waste management, transportation systems, and governance. In addition to facilitating the seamless operation of smart city infrastructures, blockchain promotes sustainable practices by ensuring accountability, reducing fraud, and optimizing resource utilization. This study looks at the different applications of blockchain technology in smart city management and how it helps achieve sustainability goals. The possible advantages and implementation techniques of integrating blockchain technology with smart city services systems are examined in this article. In fact, the study highlights several benefits, such as a lower chance of data breaches, better interoperability across various systems. The article also discusses the logistical and technical obstacles to blockchain adoption, including the requirement for established protocols, scalability, and compatibility with legacy systems.