This chapter details the many advantages of utilizing peers as change agents in behavioral interventions, including being a readily available and free resource, increasing opportunities to respond, promoting generalization, being socially valid and culturally relevant, increasing student engagement with intervention, providing access to natural reinforcement, promoting social skill development, and supporting the development of peer social relationships. The chapter also positions peer-mediated interventions as relevant to the development of children and highlights the value and usefulness of identifying the behaviors the intervention is targeting and then emphasizing the importance of the peer’s role. This chapter also discusses the research supporting the effectiveness of peers as interventionists, indicating that they can be reliably trained to carry out interventions in schools.