This chapter answers such questions by outlining a programme derived from the social identity framework that seeks to improve health by enhancing group-based social relationships. The programme, Groups 4 Health (also referred to as G4H), aims to empower people to realise these networks and to provide them with strategies to manage these networks independently in the longer term. This chapter explains why G4H is needed and we summarise preliminary data that speak to its effectiveness. Importantly, from a social identity perspective, it is not group delivery per se that is the critical mechanism through which such interventions deliver health benefits. Instead, the active ingredient that produced beneficial health effects in all studies was the increased sense of connectedness and belonging that resulted from engagement in meaningful group activity. In showing that social identity theorising not only allows us to better understand the social determinants of health but also to take steps to harness the positive potential of meaningful social identities.