Background: About one third of youth in the United States are overweight or obese and African American youth are at an increased risk for pediatric overweight and obesity as well as their complications. Physical activity has been identified as one determinant of overweight and obesity, and school bullying has been found to be associated with decreased physical activity. Guided by the Transactional Stress and Coping Model, this study examines how school bullying might impact the physical activity of white and African American healthy weight and overweight youth. Methods: Existing, nationally representative, and complex survey data (N = 4509) from the 2005-2006 United States Health Behavior in School-Aged Children (HBSC) were analyzed using multiple group structural equation modeling to evaluate study questions. Results: Support for the hypothesized model was found such that bullying negatively impacted physical activity by way of increasing internalizing symptoms. Possible evidence for parental support, but not peer support, as a protective factor was also found. Results were generally similar for all groups, though some differences are discussed. Conclusion: School bullying is a risk factor for reduced physical activity, regardless of race-ethnicity and weight. Implications for school health professionals are discussed.