Adolescence is a time during which positive adults outside the familial context may be most influential to development. A growing body of research on naturally occurring mentors has found favorable outcomes for youth who have these types of positive adult figures in their lives. Less is known, however, about how these naturally occurring mentors influence youths’ development in the long-term. This study examines the long-term outcomes related to having a naturally occurring community mentor in adolescence. Results from longitudinal analyses of a nationally representative sample of adolescents revealed that having a mentor in adolescence was related to higher educational attainment, lower criminal activity, higher psychological well-being (i.e., optimism, self-efficacy, and lack of depressive symptoms), and greater romantic relationship satisfaction in adulthood. Additionally, a taxonomy of mentoring functions was created from qualitative responses and drawing upon the youth, work, and academic mentoring literature. This taxonomy aims to serve as a framework for understanding the functions of youth mentors to provide a foundation for future research. Implications of findings and future directions are considered.