BACKGROUND: Venezuelan migrants in South America are at heightened risk for mental distress due to factors such as discrimination, unstable employment, and gender-based violence (GBV). Adolescent girls are an especially vulnerable group, with family dynamics playing a crucial role in this population's mental health status. This study explores how gendered household composition is associated with the mental health and well-being of forcibly displaced adolescent girls in Colombia. METHODS: This cross-sectional analysis employs baseline data from a pilot randomized controlled trial evaluating "Sibling Support for Adolescent Girls in Emergencies" (SSAGE), a whole-family, gender-transformative program aimed at improving adolescent girls' mental health and well-being. Data were collected from 186 adolescent girls. Key outcomes of interest included the Revised Children's Anxiety and Depression Scale (RCADS-25) and the Rosenberg Self-Esteem Scale (RSES); predictors of interest comprised the presence of various individuals residing in the household and a measure of the number of household tasks performed by girls in the last two weeks compared to an adolescent male in the household. Linear regression models were used to estimate the relationships between predictors and outcomes for younger and older adolescent girls, separately. RESULTS: Living with a male relative other than a father, brother, or grandfather was associated with higher anxiety and depressive symptoms and lower self-esteem for 13-16-year-old girls, as compared to not living with such a male relative. Adolescent girls ages 13-16 years old who reported performing a greater number of household tasks relative to their adolescent male counterpart were found to have lower self-esteem scores. For 17-19-year-old girls, living with a mother and sister was associated with lower anxiety and depressive symptoms and living with a mother was linked with greater self-esteem as compared to those not living with those family members. Additionally, 13-16-year-old girls who reported performing a greater number of household tasks relative to their adolescent male counterpart were found to have lower self-esteem scores. CONCLUSIONS: Findings underscore the significance of household gender composition in relation to the mental health and self-esteem of forcibly displaced adolescent girls. Findings highlight the potential protection of a gender-transformative approach within family-centered interventions to improve forcibly displaced girls' well-being.