Although peer mentors play a prominent role in supporting higher education experiences for people with intellectual and developmental disabilities (IDD), little is known about these college students and the factors leading to their decision to become involved in this particular experience. We examined the motivations, experiences, and expectations of 250 peer mentors attending five diverse universities offering inclusive postsecondary programs for students with IDD. Nearly all (93.7%) of the entering peer mentors had prior disability-related experiences and almost all identified a combination of personal and professional reasons for involvement. Peer mentors anticipated an array of personal benefits as a result of their participation, although beliefs about some areas of potential impact were more mixed (e.g., improvements in grades, study skills, social status). Views regarding the extent to which students with IDD can participate in different aspects of campus life reflected high expectations; predictions about these students' postgraduation experiences were more modest and mixed. We offer recommendations for research and practice aimed at identifying and engaging peers in supporting inclusive college experiences.