This research investigated how the level of disruptive behavior and friend influence on disruptive behavior varies across classrooms in relation to teacher emotional support. Data were collected from 48 fifth- and sixth-grade classrooms (N = 879 students) and included classroom observations at Wave 1 and student reports of their disruptive behavior and peer nominations of their friends at Waves 1 and 2 (fall and spring of the school year, about 6 months apart). In the fall, there were no differences in the level of disruptive behavior between classes that were low versus high in teacher emotional support. However, by spring, disruptive behavior was higher in classes with low teacher emotional support compared to classes high in teacher emotional support. Social network analyses, conducted with stochastic actor-based models, indicated that students were more likely to become similar to their friends in regards to disruptive behavior in classes low in teacher emotional support compared to classes high in teacher emotional support. Thus, the level of disruptive behavior and students' susceptibility to friend influence on disruptive behavior depend on the nature of the classroom context. This study contributes to a growing body of research showing that teachers play an important role in shaping the nature of peer relationships in the classroom.