Researchers consider motivation a key determinant of physical activity. In physical education (PE) and youth sport, the more children and adolescents evaluate their teachers and coaches to be autonomy supportive, as opposed to controlling, the more self-determined they are in their motivation. Therefore, it appears valuable to help PE teachers and youth sport coaches optimize their interactions with the individuals they work with. This study was designed to systematically review the literature related to autonomy support interventions with PE teachers and youth sport coaches. After relevant databases were searched and duplicates were removed, 1,523 potentially pertinent articles were found. These were subsequently screened based on specific inclusion criteria. This systematic review process helped identify 21 studies that were included for further analyses. Overall, the interventions were frequently successful in enhancing PE teachers' and youth sport coaches' behavior. Additional research appears justified to foster self-determined motivation among children and adolescence.