Youth sport is a key physical activity opportunity for children and adolescents. Several factors influence youth sport participation, including social factors, but this has not to date been clearly delineated. This study is a scoping review to survey the literature on the influence of family and peers on youth sports participation. The review identified 111 articles of which the majority were cross-sectional, included boys and girls, and were conducted primarily in the United States, Canada, Australia, and the United Kingdom. The articles were grouped into 8 research themes: (1) reasons for participation, (2) social norms, (3) achievement goal theory, 4) family structure, (5) sports participation by family members, (6) parental support and barriers, (7) value of friendship, and (8) influence of teammates. Friendships were key to both initiation and maintenance of participation, parents facilitated participation, and children with more active parents were more likely to participate in sport. Less is known on how family structure, sibling participation, extended family, and other theoretical frameworks may influence youth sport. The review suggests that social influences are important factors for ensuring participation, maximizing the quality of the experience, and capitalizing on the benefits of youth sport. Future research studies, programs, and policies promoting and developing evidence-based youth sporting experiences should consider social influences on youth sport participation
