Cities generate unprecedented data from sensors, satellites, mobile devices and infrastructure. CEE 420 explores the transformative role of AI and machine learning in harnessing this data to model and improve urban systems. Students gain foundational skills in spatial data science, predictive modeling, graph learning, computer vision, and LLMs. Through hands-on coding and a semester-long project with the Municipality of Princeton, students tackle real-world challenges in autonomous mobility, climate resilience, and smart cities. We also critically examine algorithmic governance to navigate privacy, fairness, and bias.