Subway systems have long been a principal form of urban public transport. Subway systems affect urban development in many aspects such as land use, travel behaviour, and service industries including tourism. Tourism nowadays makes a significant contribution to economic success and yields social benefits for cities and countries. Transport can have a considerable impact on tourists' experiences at destinations. In many cities, tourists comprise a considerable proportion of public transport users, especially during holiday periods, and subways, as a speedy, convenient, accessible, affordable, and comfortable travel choice, are used by many tourists. With an increasing number of cities with subway development (existing and planned), growing numbers of domestic and international tourist trips, and global interests in growing the tourism industry, it is time to investigate the relationship between subways and tourism to identify their contribution to tourism at destinations. This international overview explores tourism facilities and subway stations and networks, tourism-related architecture and design of subway stations, subway-related travel behaviour and perceptions of tourists, and subways and sustainable tourism. It confirms the close spatial relationship between subways and tourism facilities, the subway station's role as a new heritage frontier, the subway as the preferred transport mode of many tourists, and the opportunities and challenges that subways present to sustainable tourism. This overview is significant in that it bridges subway systems and tourism in a comprehensive way. It provides important implications for subway-related transport policies and practices, as well as suggestions for future research.