Empathy is fundamental to social functioning. Although empathy involves sharing the emotional experience of another, research also highlights the importance of distinguishing the self from the other for optimal empathic responding. Without adequate self-other distinction, sharing another person's emotions can induce personal distress, a self-focused aversive reaction that often leads to withdrawing from the situation, rather than empathic concern, an other-oriented response of care. To date, no work has examined the psychological factors that might facilitate such self-other distinction in the context of empathy. We show that self-concept clarity (SCC), the extent to which the self is clearly defined, coherent, and temporally stable, predicts empathic responding. In Study 1 (N = 453, student sample), we show that low SCC is associated with more dispositional empathic personal distress and less empathic concern. We replicate these dispositional associations in Study 2 (N = 319, community sample) and, using Batson's classic Katie Banks paradigm, show that these associations hold in an actual empathy-inducing situation. Moreover, in Study 2, SCC predicts helping behavior, an effect that is mediated by feelings of personal distress and empathic concern. Finally, in Study 3 (N = 658, community sample), we again use the Katie Banks paradigm but in an experimental framework; consistent with Study 2, state SCC predicts empathic personal distress, empathic concern and helping behavior. Our findings highlight the importance of a clear, coherent and stable self-concept for empathy, and suggest that interventions aimed at increasing empathy may be futile in the presence of a weak and unclear sense of self. (PsycInfo Database Record (c) 2022 APA, all rights reserved).