Recent reform in U.S. school systems has focused on closing racial achievement gaps, but despite great efforts, are children being socially left behind? We know from prior research that adolescents see their relationships with peers, teachers, and parents as defining aspects of their lives - and that the absence of these relationships is linked with a host of negative outcomes. Previous work also suggests that racial/ethnic and immigrant minorities may lack positive relationships with key actors in their lives. Minority youth face racial discrimination in and out of school, and many newcomers to the United States find it difficult to adapt to their new surroundings during the unsettled period of adolescence. Having limited social relationships, particularly within the school context, may prevent minority immigrant youth from learning the norms and expectations of the mainstream. However, little work has examined national patterns in social isolation, an in particular, among racial/ethnic and immigrant youth populations. My dissertation will address these gaps in literature by focusing on the social relationships in the lives of racial/ethnic and immigrant youth. Using the Education Longitudinal Study of 2002 (ELS:2002), a nationally representative sample of U.S. high school sophomores, I will examine interactions between young people and their peers, teachers, and the relationship between teachers and their parents. In this project, I extend previous scholarship on the social relationships in the lives of adolescents in a number of ways. First, my analysis will reveal broader patterns of social disengagement using a nationally representative sample of U.S. youth. Second, I will examine three major types of social interactions that shape the lives of adolescents: interactions with peers, teachers, and the communication between teachers and parents. Third, I will consider patterns of disengagement among racial/ethnic minority and immigrant young people. Results will provide scholars, policymakers, and practitioners with a clearer understanding of the social lives and relationships of students in the U.S. school system.