Research Findings: We examined whether early childhood preservice teachers’ emotional competence and commitment to social emotional learning moderated associations between their beliefs about social justice and self-reported tolerance for and conceptions of the negative costs of Black preschool boys’ challenging classroom behavior. The 164 participants were mostly White and female. Participants reported on their social justice teaching beliefs, emotional competence, and commitment to social emotional learning. Tolerance for Black boys’ challenging behavior and perceptions of the likely outcomes of behavior were assessed via hypothetical vignettes. Participants with teaching experience scored higher on emotional competence. Black boys were perceived as more likely to experience greater negative academic costs for challenging behavior. The association between social justice teaching beliefs and conceptions of Black boys’ challenging behavior as having high negative social costs was positive for preservice teachers high in emotional competence, but negative when emotional competence was low. The association between social justice teaching beliefs and conceptions of Black boys’ challenging behavior as having high negative social costs was also positive for participants low in the commitment to social emotional learning. Practice and Policy: Results are discussed in relation to early childhood teacher preparation for culturally responsive instructional and classroom management practices. (author abstract)