The current study examined school variations in academic engagement norms and whether such norms affect those most susceptible to peer influence. We presumed that behaviors associated with perceived popularity make norms salient and are most likely to affect socially marginalized (rejected) youth. Focusing on differences across 26 middle schools, the main aim was to test whether academic engagement norms moderate the association between peer rejection and subsequent academic difficulties. The U.S. public school sample included 5,991 youth (52% girls): 32% Latino/a, 20% White, 14% East/Southeast Asian, 12% African American, and 22% from other specific ethnic groups. Multilevel models were used to examine whether engagement norms moderated the association between sixth-grade peer rejection and changes in grade point average (GPA) and academic engagement across middle school (i.e., from sixth to eighth grade). Consistent with our contextual moderator hypothesis, the association between peer rejection and academic engagement was attenuated--and in the case of GPA eliminated--in schools where higher engagement was a salient norm. The study findings suggest that the behaviors of popular peers affect those on social margins and that academic difficulties are not inevitable for rejected youth.