Sport is the most popular extra-curricular activity for youth across Canada and has been identified as an important environment to foster psychosocial development in youth. It is particularly important for youth who face multiple barriers and vulnerabilities, as identified in Stepping Up: A Strategic Framework to Help Ontario's Youth Succeed by the Ontario Ministry of Children and Youth Services. This Research to Practice report summarizes the current state of research on youth development within community-based sport and/or physical activity programs for youth, both theoretically and empirically. Moreover, we identify strategies and best practices for fostering youth development within community-based sport and/or physical activity contexts. Finally, we provide recommendations for community-based youth sport programmers to incorporate positive youth development (PYD) frameworks, approaches, and strategies into their programs. This report provides information for youth sport programmers and practitioners, particularly those working with youth facing barriers, on how to deepen the impact of sport programs by intentionally structuring these programs to support psychosocial development.