Supportive Non-Parental Adults (SNPAs), or non-parental adults who provide social support to youth, are present in the lives of many adolescents; yet to date, a guiding framework for organizing the existing literature on the provision of support provided by multiple types of SNPAS, such as teachers, natural mentors, and extended family members, as well as to inform future research efforts, is lacking. The aim of the current paper is to utilize the well-established lens of social support to integrate, across this broad range of literatures, recent findings regarding associations between SNPAs and four indices of adolescent psychosocial adjustment: academic functioning, self-esteem, and behavioral and emotional problems. Beyond offering an integrative framework for understanding the link between SNPAs and adolescent functioning, the issues reviewed here have potentially far-reaching consequences for adolescents and their families, as well as the professionals working with adolescents and their families in the health care, school, and community settings.