Urban development is undergoing a radical transformation through the convergence of technology, environmental stewardship, and infrastructure resilience. Environmental engineering, infrastructure & smart cities explores solutions that enhance resource efficiency, pollution mitigation, and real-time system responsiveness in rapidly urbanizing regions. From green buildings and low-impact stormwater systems to AI-integrated traffic control and sensor-based pollution monitoring, cities are evolving into living laboratories. Environmental engineers now work at the interface of data science and design, crafting systems that are adaptive, decentralized, and climate-resilient. Smart urban planning integrates environmental justice, public health, and carbon neutrality goals. Environmental Engineering, Infrastructure & Smart Cities thus represents a forward-looking agenda, where technological innovation aligns with sustainable living environments.