This chapter examines the social effects of sport, focusing on the contribution of sport, particularly organized sport in clubs, to the development of social capital and the promotion of social integration. The chapter demonstrates that sports provide important social spaces that foster trust, social networks, civic engagement, and a sense of belonging. These spaces strengthen social cohesion. However, empirical findings also reveal that these effects are not automatic. Integration depends on club goals, resources, participation intensity, and social climate. Furthermore, exclusionary dynamics may occur. Overall, the chapter demonstrates that sports have considerable potential to generate valuable social outcomes that can also be economically relevant. However, it highlights the need for further research, especially regarding the monetary valuation of social effects.