The main aim of our research was to describe the comprehensive picture of relationships between identity and well-being with a cross-national perspective. We examined identity considering the interplay of three processes (i.e., commitment, in-depth exploration, and reconsideration of commitment) and we treated well-being as a multidimensional latent variable, whose indicators were subjective well-being, psychological well-being, and social well-being. Participants were 1,086 (60.6 % female) emerging adults from Italy, Poland, and Romania. They completed self-report measures of identity and well-being. We adopted a structural equation modeling approach and we tested associations between identity and well-being for university students (taking into account educational identity) and working emerging adults (considering job identity). For all countries and in both identity domains findings indicated that well-being was consistently associated with high commitment, high in-depth exploration, and low reconsideration of commitment. Implications of these findings are discussed.