Pleasantness and meaningfulness are sometimes seen as opposing pursuits. Yet past research has found that the pursuit of meaning often leads to pleasure. In four longitudinal studies—three observational, one experimental, ranging from 5 weeks to 18 months—we investigated an inverse process, whereby specific kinds of pleasant states can foster a sense of meaning in life. We hypothesized that perceptions of positivity resonance, a form of coexperienced positive affect characterized by mutual care and synchrony, are experienced as particularly meaningful in the moment and, over time, build social resources (e.g., supportive relationships and communities) that foster an enduring sense of meaning in life. Results indicate that perceived positivity resonance is associated with perceived meaning both between- and within-persons, links that emerge independently of overall pleasant emotion and social interaction quantity. Perceived social resources mediate between-persons links, and changes in perceived social resources mediate longitudinal links. Overall, these findings suggest that coexperienced, caring, and synchronous pleasant states may be uniquely suited to cultivating a person’s sense that life is meaningful.