Research shows that exposure to local neighborhood violence is associated with students’ behavior and engagement in the classroom. Given the social nature of schooling, these symptoms not only affect individual students but have the potential to spill over and influence their classmates’ learning, as well. In this study, I use detailed administrative data from five complete cohorts of students in the Chicago Public Schools (2002 to 2010), crime data from the Chicago Police Department, and school-level surveys conducted by the University of Chicago Consortium on Chicago School Research to assess the strength of this peer effect. The estimated negative relationship between peer exposure to neighborhood violent crime and individual achievement is substantial and remains after adjusting for other peer characteristics and student fixed effects. Surveys suggest these results are related to trust, discipline, and safety concerns in cohorts with larger proportions of students from violent neighborhoods.