Adolescent health and well-being is significantly influenced by the urban living environment. This study examined what health and well-being mean to adolescents and how they perceive neighborhood factors as influencing them. Interviews with 15 adolescent boys from a low socioeconomic urban neighborhood in the City of Utrecht, the Netherlands, reveal that, according to these boys, doing fun things and spending time with friends and peers underpin their health. The adolescents indicated that such activities support adolescents' subjective well-being by providing opportunities to, inter alia, develop social contacts, explore and affirm their personal identity, and negotiate social belonging. The findings show that neighborhoods can support or hinder adolescents' health and well-being by providing or limiting access to public and private spaces—such as outdoor recreation areas, organizations, sports clubs, and local stores and restaurants—where young people can gather, interact and potentially engage in paid work. Future health promotion efforts should focus on enhancing existing institutional resources, developing new ones, and improving financial support to provide all adolescents with affordable and accessible opportunities to promote their health and well-being through meaningful peer activities.