Objective <p>This study aimed to investigate the influence of physical activity on reading literacy in children aged 9–10 years and to examine the mediating role of executive function.</p> Methods <p>A cross-sectional study design was adopted, involving 293 children aged 9–10 years (Valid sample size: 282). Physical activity levels were assessed using the Physical Activity Questionnaire for Children (PAQ-C). Reading literacy (literary and informational texts) was evaluated using the PIRLS 2021 assessment. Core components of executive function—inhibitory control (Flanker task), working memory (1-back task), and cognitive flexibility (Trail Making Test, TMT)—were measured using experimental paradigms. The mediation effect was tested using the Bootstrap method with 5,000 resamples.</p> Results <p>The gender distribution of the sample was balanced. For parental education, the highest proportion of parents held high school or vocational college degrees, and the majority of household incomes were concentrated in the middle-income bracket. The mean physical activity score for children was 2.97 ± 0.76, indicating a moderate-to-low level. Girls significantly outperformed boys in both literary (17.26 ± 4.84 vs. 16.27 ± 4.55) and informational (15.37 ± 4.63 vs. 14.13 ± 5.51) reading literacy. No significant gender differences were observed in any executive function subcomponents: inhibitory control (142.74 ± 81.53), working memory (1040.43 ± 86.10), or cognitive flexibility (93.99 ± 30.73). Additionally, parental education level and household income had significant effects on children’s physical activity, reading literacy, and executive function. Pearson correlation analysis revealed that physical activity was positively correlated with both literary (<i>r</i> = 0.341) and informational (<i>r</i> = 0.319) reading literacy, indicating weak positive correlations. Physical activity showed significant negatively correlated with all executive function subcomponents (inhibitory control: <i>r</i> =-0.457; working memory: <i>r</i> = -0.431; cognitive flexibility: <i>r</i> = -0.393), suggesting weak-to-moderate negative correlations. Both types of reading literacy were negatively correlated with all executive function subcomponents. (∣r∣= ranging from 0.293 to 0.457), also representing weak-to-moderate associations. The structural equation model indicated that the total effect of physical activity on reading literacy was 0.160, the direct effect was 0.093, and the indirect effect mediated by executive function was 0.070, accounting for 43% of the total effect.</p> Conclusions <p>(1) Children’s physical activity level is positively correlated with reading literacy and can serve as a significant predictor of reading proficiency; (2) Executive function partially mediates the association between physical activity and reading literacy.</p>