The rapid urbanization of the 21st century has necessitated innovative approaches to city management and infrastructure development. The Internet of Things (IoT) has emerged as a transformative technology in smart city initiatives, enabling interconnected systems that enhance urban efficiency, sustainability, and quality of life. This comprehensive review examines the role of IoT in smart city development, analyzing key applications across transportation, energy management, environmental monitoring, and public safety sectors. We explore the technological architecture underlying IoT implementations, including sensor networks, communication protocols, data analytics platforms, and cloud computing infrastructure. The review identifies significant benefits including improved resource efficiency, enhanced citizen services, and data-driven decision making, while addressing critical challenges such as cybersecurity concerns, interoperability issues, and privacy protection. Through analysis of global case studies and emerging trends, this article provides insights into the current state and future directions of IoT-enabled smart cities. The findings suggest that successful IoT integration requires comprehensive planning, stakeholder collaboration, and robust governance frameworks to realize the full potential of connected urban environments.