In this chapter, we draw from theory and research on parent–child relationships and youth development to examine how long-term professional mentoring can support young people as they journey through childhood and into and through adolescence. We begin by situating professional mentoring within a bilateral framework of mentoring relationships. We then move to a discussion of how research on parenting, and specifically around the authoritative parenting style, can serve as a useful framework for considering how mentors can be responsive to the different developmental needs of children and adolescents. We then detail fundamental ways mentors can support and promote positive youth development, namely, through social support, emotion regulation, and attunement.