There is vast empirical evidence showing that juvenile delinquency is associated with delays in moral development, including moral judgment, empathy, and self-conscious emotions (guilt and shame). Consequently, interventions have been developed that target moral development of juvenile delinquents to reduce criminal offense recidivism. However, a comprehensive synthesis of studies examining the effectiveness of these interventions was not yet available. The present meta-analysis of (quasi-)experimental research therefore examined the effects of interventions that target moral development of youth engaged in delinquent behavior. Interventions that targeted moral judgment (11 studies and 17 effect sizes) showed a significant and small-to-medium effect on moral judgment ( d = 0.39), with intervention type as a significant moderator, but no significant effect on recidivism ( d = 0.03; 11 studies and 40 effect sizes). No (quasi-)experimental studies were found that targeted guilt and shame in juvenile offenders, and an insufficient number of studies (i.e., only two) were found to conduct a meta-analysis of interventions that target empathy. The discussion focuses on potential ways to improve moral development interventions for youth engaged in delinquent behavior, and provides suggestions for future research.