The optimization of urban management has become a priority for cities worldwide, driven by the need for sustainability, efficiency, and enhanced quality of life. The Internet of Things (IoT) is at the core of these advancements, offering innovative solutions for managing energy, water, and waste systems. However, IoT integration poses ethical and social challenges, including economic barriers, privacy concerns, interoperability issues, and the digital divide. This study examines IoT applications in energy, water, and waste management, as well as the associated challenges, drawing insights from Barcelona, Tokyo, and Singapore. By analyzing these cases, this research highlights the importance of inclusive frameworks that balance technological efficiency with social equity and ethical considerations. Recommendations are proposed to guide policymakers in adopting sustainable and equitable urban management strategies.