Very little identifiable research explores the factors impacting autistic students’ school motivation and how these factors may or may not affect their academic and well-being outcomes in secondary school and beyond, including post-secondary enrollment, employment, and their quality of life. Instead, research on autism and inclusive education mainly focuses on the efficacy of interventions aimed at teaching skills related to sensory, communication, social, and behavior. Methods: A secondary analysis of survey data from an original mixed-method study was conducted to investigate how environmental, teacher, and peer factors are associated with autistic students’ school motivation. Eligible participants were between the ages of 15 and 21. In total, 72 participants (n = 72) completed an online survey to share their perspectives on their school experiences. Subsequently, linear regression analysis was conducted to answer the research question. Results: Participants who rated their schools as having pleasant physical spaces and felt that their peers understood them as a person had higher levels of school motivation. Teachers were not found to be significantly related to students’ school motivation. Participants who shared that typing was their preferred mode of communication were less motivated to attend school than students who preferred speaking communication. Conclusions: Environmental and peer factors are related to more than the day-to-day school experiences of autistic students; they are also related to their school motivation. These findings add to the existing literature on inclusive education and positive school outcomes for autistic students and offer additional explanations of the barriers that affect autistic students’ graduation from secondary school and interest in attending post-secondary education.