This article is based on a renewed, unified functional definition of France’s urban hierarchy. Our ranking defines small towns exclusively in terms of their commercial and service functions, not according to size (population or jobs). Accordingly small towns are characterized by their function both in terms of education (presence of a high school), healthcare (a hospital with an operating theatre) and trade (a supermarket with floorspace exceeding 2,500 square metres). The population of small French towns identified using these criteria ranges from 6,200 to 35,500, with 3,500 to 19,000 jobs, depending on their regional context. Large hub-bourgs, defined as places hosting a secondary school, supermarket and nursing home, emerge as the lower limit of the urban world, interfacing with the countryside. In several ways they might count as ‘very small towns’, with a population ranging from 2,400 to 13,500, and 1,000 to 4,700 jobs. The article then analyses the population dynamic of small towns in mainland France over the past 50 years. This period has witnessed far-reaching changes: an urban then metropolitan model has gradually taken shape and gathered strength. In recent years this process has gone hand-in-hand with the demographic renewal of rural areas.