This study examines concurrent and short-term longitudinal (i.e., academic year) relations between peer network racial/ethnic diversity and indicators of social and academic competence in a sample of African American, Latino, Native American, and White sixth-grade students attending rural schools (N = 481; 50% female). Results from two-level hierarchical linear models indicated that in the fall of sixth grade, peer network diversity was positively related to teacher-rated interpersonal competence for Native American youth and to peer protection from bullying for White youth. Students in more diverse peer groups had higher teacher-reported social and academic competence in the spring of sixth grade; these associations were moderated by racial/ethnic group, emerging most consistently for students of color. Results suggest benefits of peer network diversity in early adolescence and also highlight a need to understand mechanisms through which these benefits are incurred.