<p>We investigate the effect of body image on life satisfaction across different nations both individual and country-level. This is significant since life satisfaction is associated with many desirable outcomes such as democratic stability, and subjective well-being. Previous studies present confounding results due to a single sample and culture, and few studies have mainly focused on adolescents. Thus, this study used a dataset derived from the Programme for International Student Assessment (PISA) 2018 to examine the association between body image and life satisfaction. To explore the unique impact of cultural factors, we further analyzed the moderating effects of cultural individualism and religiosity. The results indicated that body image positively correlates with life satisfaction at the individual level, and the relationship between body image and life satisfaction is negatively moderated by cultural individualism. These results indicated that cultivating adolescents’ positive body image is an effective way to improve life satisfaction in a global context, especially in collectivist cultures.</p>