Although peer-mediated interventions are an evidence-based approach for improving social and learning outcomes for students with intellectual disability (ID), their impact on participating peers has received limited attention. Knowing whether and how peers are affected could influence the extent to which these interventions are more widely adopted in schools. The purpose of this review was to (a) summarize extant research on the behaviors of peers without disabilities and their perception of interacting with students with ID, (b) identify common behaviors measured for peers, and (c) evaluate the effects of peer-mediated interventions on peers. Toward that effort, we reviewed 53 studies. Results indicate that interventions have successfully increased peers’ interactions with their classmates with ID and suggest some positive outcome for peers; however, consistent methodological gaps limit further analysis. We offer recommendations for strengthening future research involving peers within interventions for students with ID.