Background: Children with severe developmental disabilities are frequently excluded from research, and little is known about their quality of life (QoL). Using a mixed-methods approach, this study examined relationships between school factors and QoL for these children and their families. Method: 171 parents of children with severe developmental disabilities completed questionnaires. Hierarchical regression analyses were performed examining predictors of child and family QoL. Of the 171 parents, 123 responded to an open-ended question about their children's school experiences, and responses were analysed qualitatively. Results: Significant predictors of QoL included challenging behaviours, diagnoses, parent self-efficacy, social support and (importantly) school satisfaction. Seven themes related to school experiences were identified qualitatively. Conclusion: Many factors contribute to QoL. School has a significant influence on children and their parents and families. Different children have different strengths and difficulties, and school systems need to work with parents to optimise outcomes.