Supportive relationships with non-parental adult role models (aka informal mentors) are important contributors to positive development for children. Absent from research on informal mentoring relationships are studies examining parents' role in the formation and maintenance of these relationships. In this study, we examined parents' attitudes about and experiences with their children's involvement in informal mentoring relationships in two phases. Participating in phase 1 were 161 parents of children enrolled in a formal mentoring program in Canada (ages 27–69, M = 40.25 years; 93.2 % female; 6.8 % male). Participating in phase 2 was a convenience sample of 425 parents in a midwestern state in the United States (ages 23–70, M = 44.95 years; 65.9 % female; 34.1 % male). Parents completed a one-time 20-minute online survey. Parents generally held positive attitudes towards informal mentors but also reported limited involvement in − and several barriers to − fostering children's informal mentoring relationships. Barriers ranged from not wanting to be a burden on others to believing children would rather spend time with friends. Most parents reported their child had had at least one informal mentor at some point. In both phases, frequency of their child having a mentor was related to their parents having positive attitudes toward informal mentoring and to having directly asked a nonparental adult to be an informal mentor. In phase 2, parents who reported a greater sense of community and supportive social network and higher self-efficacy for facilitating mentoring relationships were more likely to have children with informal mentoring relationships. The findings have implications for including parents in efforts to increase children's access to supportive mentoring relationships.