Objectives In prior studies, mixed results have been obtained regarding the relations between mindfulness, moral judgment, and prosocial behavior. We conducted two studies to better clarify the connections between mindfulness and several moral variables. Methods In Study 1, a cross-sectional survey (N = 554) was conducted to test the possible associations between mindfulness, moral sensitivity, moral identity, and prosocial behavior. In Study 2, a randomized controlled experiment was conducted to examine the impact of a mindfulness intervention on moral identity and prosocial behavior. A total of 99 participants (n = 49, mindfulness group; n = 50, wait-list control group), all of whom were undergraduate students on an optional 11-week mindfulness-based self-exploration course, were recruited via the campus network system. Results In Study 1, we found that mindfulness, moral sensitivity, moral identity, and prosocial behavior were all positively correlated. Results of the mediation analysis suggested that dispositional mindfulness had significant effects on prosocial tendencies both directly and indirectly via the mediator variables of moral sensitivity and moral identity. In Study 2, mindfulness practice was found to significantly improve the levels of mindfulness and self-compassion in participants but only had a significant effect on willingness toward prosocial behavior for those participants with existing high moral identity.Conclusions Study 1 confirmed the predicted links between mindfulness, moral sensitivity, moral identity, and prosocial behavior. Study 2 suggested that moral identity influences the effect of mindfulness practice on willingness toward prosocial behavior. However, the underlying mechanisms and causes of this effect require further study.