This paper introduces the concept of belonging and discusses it in the context of online social networking experience and community experience considering social capital and user’s activities as nuclear concepts to understand collective actions and social relationships mediated by social media. The paper presents an empirical approach based on the study of two local communities and analyses whether interactive social technologies promote greater social involvement and higher production of social capital and participation, that results in a greater sense of belonging within communities. The results indicate a positive relationship between the use of social media and the increase of social capital and sense of belonging. Our work discusses the role and influence of social media in communitarian practices and the relevance social capital theory has as an outcome of media technologies use that result in a greater sense of belonging to a community.