INTRODUCTION: Adverse Childhood Experiences (ACEs) are associated with multiple deleterious life-course outcomes, with salient repercussions during adolescence. Evidence on vulnerable peripheral adolescents remains scarce, especially in Brazil. This study examined the association between self-reported ACEs (family/community violence, abuse, and neglect) and body satisfaction among adolescents aged 10 to 14 years living in an impoverished peripheral community of São Paulo, Brazil. METHODS: This quantitative cross-sectional investigation used 2021 baseline data from the Global Early Adolescent Study (GEAS). The sample comprised 974 cisgender adolescents aged 10 to 14 years recruited through Primary Health Care Units. Body satisfaction was measured using a four-item index derived from the Health Behaviour in School-aged Children (HBSC) instrument. ACEs were assessed through a standardized instrument covering 11 adversity categories. Descriptive, bivariate, and multiple linear regression analyses were conducted, adjusting for sociodemographic and contextual variables. RESULTS: ACE exposure was frequent: 81.2% of adolescents reported at least one adversity and 33.8% reported four or more exposures, particularly girls. Fear of emotional aggression (61.7%), emotional neglect (58.8%), and physical neglect (49.0%) were most frequent. Girls showed lower body satisfaction than boys. Emotional neglect, bullying, fear of emotional aggression, physical neglect, and caregivers' emotional distress remained significantly associated with lower body satisfaction means. CONCLUSION: Frequent reports of ACEs, particularly emotional aggression and neglect, suggest that body satisfaction during early adolescence is closely related to relational experiences and gender differences. These findings highlight the need for health and educational strategies addressing violence and neglect in vulnerable peripheral contexts.