Background: Although physical activity can play a positive role in psychosocial development, few studies have longitudinally examined the relationship between physical activity from physical education (PA from PE) and perceived peer acceptance (PPA). Methods: Data from the Korean Children and Youth Panel Survey were used with 1908 elementary students from the first (age 10 years) to the 4-year panel (age 13 years), and 1954 middle-school students from the first (age 14 years) to the 4-year panel (age 17 years). We analyzed the data using latent curve modeling. Results: In childhood, an increase in the amount of PA from PE over time positively corresponds with positive linear tendency of PPA over time. In adolescence, a decrease in the amount of PA from PE over time negatively corresponds with positive linear tendency toward PPA over time. Thus, PPA changes are positively associated with PA from PE across both childhood and adolescence. Conclusions: Our data suggest that the amount of PA obtained in PE is salient to perceived peer acceptance of both children and adolescents. Other variables (eg, friendship, self-presentational processes) that might affect this relationship should be explored.