<strong>Purpose:</strong> Physical activity promotes a positive physical self-image, but less is known about whether the positive effect covers the general self-evaluation of adolescent appearance. This study aimed to further explore the associations between physical activity and body-esteem in Finnish adolescents, via a country-representative cross-sectional study design. <strong>Methods:</strong> The data for the study were drawn from the Finnish component of the Health Behaviour in School-aged Children (HBSC) study (2014), using surveys from 15-year-old adolescents (n=1956, mean age 15.8 years) from 122 schools. Self-evaluations of body or appearance were measured by the Body-Esteem Scale for Adolescents and Adults (BESAA). A mixed effects linear regression analysis for body-esteem was conducted separately for boys and girls. The explanatory variables were (i) self-reported moderate-to-vigorous physical activity (MVPA), (ii) weight status, (iii) self-esteem, and (iv) socioeconomic status. The covariates used in the models were maturation state and ethnic background. <strong>Results:</strong> The body-esteem score was highest among adolescents who reported engagement in MVPA corresponding to the international recommendation for adolescents’ physical activity. The positive association between MVPA and body-esteem was found even when it was considered in conjunction with other body image-related factors, but only among boys. The variance in MVPA explained 5.0% of the body-esteem variance in the model for boys (Model R<sup>2</sup> = 26.3%). <strong>Conclusions:</strong> The physical activity of young people should be further promoted for a variety of health reasons, including its positive association with higher body-esteem. However, consideration should be given to gender differences and other factors related in this complex association.