Objective: To analyze the status of outdoor activities on weekends among children and adolescents of different educational stages in Shanghai and their impact on myopia, so as to provide a basis for formulating more specific prevention and control protocol of myopia. Methods: From September to October 2022, a stratified cluster random sampling method was employed to select 84 schools (27 kindergartens, 21 primary schools, 15 junior high schools and 21 high schools) across Shanghai, enrolling a total of 28 654 children and adolescents aged 4 to 18 for the study. Ophthalmic examinations were conducted to ascertain the prevalence of myopia among children and adolescents. Additionally, a questionnaire survey was administered to collect data on outdoor activity duration and associated factors. Multivariate Logistic regression analysis was utilized to investigate the associated factors of outdoor activity levels on weekends. Results: The overall myopia detection rate among children and adolescents was 58.4%, with a higher rate observed in girls (59.2%) compared to boys (57.6%). The myopia detection rates for children and adolescents with an average daily outdoor activity duration of ≥2 h and <2 h on weekends were 54.6% and 68.8%, and the differences were statistically significant ( χ 2=8.12,460.89, P <0.01). Multivariable Logistic regression analysis revealed that girls ( OR =0.80), those with a myopic parent ( OR =0.68), schools from urban districts ( OR =0.72), higher education stages (primary school: OR =0.65, junior high school: OR =0.24, high school: OR =0.14) and spending≥2 h/d on homework during weekends ( OR =0.57) among children and adolescents were less likely to engage in outdoor activities for ≥2 h on weekends ( P <0.01). After incorporating gender, parental myopia status, educational stage, school location, average daily duration on weekends for spending on homework, electronic product usage and outdoor activities as dependent variables in a multivariate Logistic regression analysis, the results showed that children and adolescents with an average outdoor activity duration for ≥2 h on weekends had a lower risk of myopia ( OR =0.86, P < 0.01). Conclusions The level of outdoor activity among children and adolescents on weekends needs to be improved. Outdoor activities on weekends is an associated factor for myopia among children and adolescents. Particularly, girls, those with myopic parents, schools from urban districts, and spending long hours on homework during weekends among children and adolescents require increased attention.