Aims:Overweight and obesity in children and adolescents are major public health challenges associated with psychosocial adversity and unfavourable lifestyle. Exposure to interpersonal violence, such as sexual abuse, violence and bullying, could represent precursors, accelerating or sustaining factors. Methods: The Young-HUNT 3 study, 2006–2008, is a population-based, cross-sectional, cohort study of Norwegian youth that includes self-report data on exposure to interpersonal violence; pubertal status and timing; socioeconomic, psychosocial, and lifestyle factors; and clinical anthropometric measures. A cohort of 10,464 adolescents aged 12–20 years from Nord-Trøndelag County were invited to participate. Body mass index served as the outcome in the simple and multiple linear regression analyses. Results: The response rate was 72.3% (7564), and 49.9% (3777) of the respondents were girls. A robust and significant relationship between interpersonal violence and increased BMI for both genders was found. Importantly, interpersonal violence remained significantly correlated with higher BMI following adjustment for pubertal development, socioeconomic and psychosocial adversity and unfavourable lifestyle factors in both genders, although most evident in girls. Adjusted regression coefficients (95% confidence intervals) for the relationship between interpersonal violence and BMI were 0.33 (0.01, 0.65) for 1 type and 0.89 (0.37, 1.41) for 2 types, compared to no exposure in girls, and 0.40 (0.09, 0.71) for 1 type and 0.35 (−0.09, 0.79) for 2 types of interpersonal violence in boys. Conclusions: The empirical evidence of consistent associations between interpersonal violence, related psychosocial and lifestyle factors, and body fatness, indicates that these features play important roles for adolescents struggling with overweight.