The eudaemonic tradition asserts that life engagement, that is the pursuit of a meaningful way of living, is an important element of well-being. Self-identity theory posits that individuals' identities significantly contribute to their sense of meaning and belonging, which in turn boost well-being. The present study aimed to establish the extent to which self-identities are predictors of well-being and whether they are subsumed within the life engagement construct. An opportunity sample of Singaporeans (n = 269) aged 18-35 (M = 23.88,SD = 4.52) completed the Aspects of Identity Questionnaire, Warwick-Edinburgh Mental Well-Being Scale and Life Engagement Test. Correlational analysis showed that personal, social, relational and collective identities were significantly associated with life engagement and well-being. However, multiple regressions demonstrated that life-engagement subsumed collective and relational identity almost completely, and also accounted for a significant amount of the variance in personal and social identities in the prediction of well-being, broadly supporting the eudaemonic model. It was shown that social and personal identities were predictors of well-being beyond life engagement, possibly because these identities satisfy some of psychological needs that promote various benefits that are independent of life engagement, yet still important for well-being. It is suggested that these differences in the salience of identity types to well-being may be indicative of changes in the sense of identity among young Singaporeans that have arisen as a result of social policy or possibly changes in the ways of identity expression in the Internet. The implications of the findings are discussed and recommendations made for future research.