The purpose of this research was to examine the extent to which social support and wider community perceptions/engagements among adolescents are connected with well-being. We compared adolescents in two different societal contexts, Florida in the United States and County Offaly, in Ireland, and posed the questions: What are the key predictors of subjective well-being from the various sources of support, and to what extent does the impact of social support on well-being vary across these two societies? Questionnaires were completed and returned for 607 respondents (322 in the Irish study and 285 in the Florida study). A variety of scales were adopted and designed to operationalize our key concepts of: Adolescent well-being, social support, school satisfaction, neighbourhood quality of life and community/voluntary participation. Our results indicate that informal social support and school satisfaction were the strongest predictors of youth well-being in both locations, despite some differences in terms of individual influencing variables. From informal sources, emotional support from friends and advice/concrete/esteem support from parents emerged as important predictive dimensions. Liking school, perceptions of doing well in school were the main predictors of school satisfaction in Ireland while, in Florida, student camaraderie and the experience of bullying emerged as significant.