Purpose  Parent–adolescent shared responsibility for diabetes care is advocated by experts to achieve beneficial diabetes and psychosocial outcomes for adolescents with type 1 diabetes. Parental autonomy support may be a way to facilitate this sharing. In this dyadic study, we examined parental diabetes‐specific autonomy support experienced by adolescents with type 1 diabetes and their parents (n= 89 dyads), and its association with their experience of shared diabetes care responsibility.Methods  Path analysis was used to test an Actor–Partner Interdependence Model for parental autonomy support effects on shared responsibility. This was a secondary analysis of data from 89 parent–early/mid‐adolescent dyads.Results  Actor effects were identified. Parents' and adolescents' perceptions of parental autonomy support were associated with their respective reports of shared diabetes care responsibility. One partner effect was identified. Adolescents' reports of parental autonomy support were associated with parents' reports of shared responsibility. Parents and adolescents held similar views of autonomy support but discrepant views of shared responsibility. Older adolescents perceived less parental autonomy support.Conclusion  Increasing parental autonomy support may facilitate parent–adolescent sharing of diabetes care responsibility. Adolescent and parent perceptions influence each other and need to be considered when working with them to strengthen parental autonomy support.