As the world progresses towards a more connected and technologically advanced future, the evolution of wireless communication technologies plays a pivotal role in shaping the landscape of smart cities and the Internet of Things (IoT). This paper provides a comprehensive review of the anticipated impact and potential contributions of 6G technology in supporting and enhancing the infrastructure of IoT and smart cities. The introductory section outlines the historical context of wireless communication, highlighting the transformative journey from 1G to the upcoming 6G. Emphasis is placed on the escalating significance of IoT across various sectors and the need for advanced communication technologies to meet the growing demands of a connected world. The paper explores the defining characteristics and advancements offered by 6G, distinguishing it from its predecessors, particularly 5G. Attention is given to its capabilities in terms of low-latency communication, high data transfer rates, and efficient spectrum utilization. Special focus is directed towards the integration of IoT with 6G technology, elucidating how the enhanced connectivity and massive device handling capabilities of 6G can revolutionize the functioning of IoT devices. The implications of 6G on smart cities infrastructure are discussed, highlighting its role in improving communication between smart devices, enabling real-time data exchange, and supporting resource-intensive applications through edge computing. However, challenges and considerations are not overlooked, as the paper delves into the security and privacy concerns associated with a highly connected environment. Additionally, the discussion extends to the practical challenges of upgrading existing infrastructure and the financial implications of widespread 6G implementation. The paper concludes by envisioning the future implications and opportunities that 6G technology presents. It explores potential applications across diverse sectors and emphasizes the economic and social impacts, including job creation, economic growth, and improvements in the quality of life within smart cities. This paper aims to provide a holistic overview of the future role of 6G technology, offering insights into its potential to reshape the landscape of IoT and smart cities infrastructure. The findings contribute to the ongoing discourse on the intersection of advanced communication technologies, IoT, and urban development in the ever-evolving technological landscape.