PurposeSports participation is associated with children’s health and wellbeing; however, existing evidence is predominantly based on cross-sectional studies. This study examined the longitudinal association of sports participation with psychosocial wellbeing of Australian children. MethodsData were from five waves of the Longitudinal Study of Australian Children aged 6–7 years in 2010 (n = 4,242) and followed up until 2018. Outcomes were assessed using the Strengths and Difficulties Questionnaire and the Pediatric Quality of Life Inventory. Sports participation was measured using two items assessing regular participation in team and individual sports. ResultsMultilevel mixed effects modeling showed that any sports participation was beneficially associated with psychosocial wellbeing. Boys who participated in team sports had 1.78 point lower difficulties score (β = −1.78; 95% confidence interval: −-2.01,−1.55), while this was 0.58 points lower for individual sports (β =−0.58; −0.81,-0.34). In girls, difficulties score was 1.22 point lower for team sports (β = −1.22; −1.44,-1.00) and 0.49 point lower for individual sports (β = −0.49; −0.71,-0.26). Sports participation was positively associated with better quality of life with team sports (β = 4.72; 4.15,5.28 for boys; β = 3.44; 2.87,4.00 for girls) offering more benefits than individual sports (β = 1.00; 0.83,1.98 for boys; β = 1.40; 0.83,1.98 for girls). Participation in both team and individual sports had the strongest benefits. Prolonged engagement in sports was associated with better psychosocial wellbeing in a dose-dependent manner. DiscussionRegular participation in any sports can benefit children's wellbeing with team sports being more beneficial than individual sports. Encouraging children to regularly participate and remain engaged in sports can help to optimize their psychosocial wellbeing.