The rapid progress of urbanization not only enables higher populations living in modern cities, but also engenders many “urban diseases,” such as air pollution, traffic congestion, and increased energy consumption. Mobile big data, with advanced communication and information technologies, can be collected through a variety of data sources, including cellular networks, the Internet of Things (IoT), social networks, and so on. This allows detailed analysis on the moving patterns of citizens and behaviors of devices deployed in urban areas, which helps grasp the outlines and the inner flows of cities. Based on those observations, prediction of events and their involved crowds and departments in cities can lead the city to become more intelligent and greener. The articles in this special section offer a comprehensive overview of the state-of-the-art developments in technology, application, and theory for mobile big data for urban analytics.