This article focuses on what social structure is favorable for making solidarity tourism sustainable, especially in the small village of Camini in the Calabria region of southern Italy. Since the turn of the century, more immigrants from Africa and Asia have been moving into Camini. With the support of the Eurocoop Camini “Jungi Mundu,” Camini has been collaborating with volunteers from around the globe and host residents to establish a multicultural society with immigrants. In recent decades, solidarity tourism has been functioning well in Camini. While tourism development has been projected in small towns and villages in many regions of the world, thanks to solidarity tourism, Camini has outstanding social networks for mutuality and interactivity. What type of solidarity among community members is needed to make solidarity tourism sustainable? This article introduces two types of solidarity proposed by French sociologist Emile Durkheim: mechanical and organic solidarity. Organic solidarity is revealed to be preferable for solidarity tourism, as all community members can feel solidarity accompanied by inseparability and shared responsibility in each of their roles. The validity of organic solidarity is discussed from primary interview data obtained through a field survey conducted in Camini. Moreover, we considered a decentralized network of community members and indicated that such a network with inseparability and shared responsibility is well aligned with organic solidarity as advocated by Durkheim. The results have indicated that organic solidarity can be a promising social structure for making solidarity tourism sustainable, which can also contribute to community engagement and empowerment.