Previous research has shown that adolescents´ social media use predicts increased body dissatisfaction. However, little is known about social environmental factors that may attenuate this relationship. This study examines one such potential moderating social environmental factor: positive parent–adolescent relationships. A school-based survey was conducted among 440 adolescents aged 12 to 19 ( M = 14.9, SD = 1.8, 47% female). On average, social media use was positively associated with body dissatisfaction, but this relationship was weaker among adolescents who reported a more positive mother–adolescent relationship. Positive father–adolescent relationship did not moderate the association between social media use and body dissatisfaction. These findings may indicate that adolescents’ social environment, notably the relationship they have with their mothers, can protect them against the detrimental effects of social media use on body dissatisfaction. However, longitudinal and experimental studies are needed to examine the direction of effects and test the validity of this interpretation.