Studies persistently show disparities in exclusionary discipline across racial/ethnic groups in U.S. schools. Using administrative data from kindergarteners through fifth graders in Indiana, we examine the effects of student-teacher race/ethnicity matching on disciplinary outcomes. We find that Black students exhibit lower rates of suspension and expulsion when they study with Black teachers--driven mainly by fewer defiance and profanity offenses. By contrast, for Latinx and White students, having a teacher of the same race/ethnicity is not associated with suspension and expulsion. In light of the shortage of Black teachers in the teacher workforce, our findings underscore the vulnerability of Black students to exclusionary discipline in the early stages of schooling.