Background: Physical activity is important for children’s health, and identifying factors associatedwith their physical activity is important for future interventions and public health programs.Purpose: This study sought to identify multidimensional correlates of preschool children’s physical activity.Methods: The social– ecological model (SEM) was used to identify constructs potentially associated with preschool children’s physical activity. Data were collected from 1004 preschool children, aged 3–5 years, and parents in 2008 –2009, and analyzed in 2010 –2011. Physical activity was measured over 8 days using ActiGraph accelerometers. Parents completed a comprehensive survey. Generalized linear modeling was used to assess associations between potential correlates and percentage of time spent in physical activity.Results: Correlates of physical activity were found across all the domains of the SEM and varied between boys and girls and week and weekend days. Age was the only consistent correlate, with children spending approximately 10% less time in physical activity for each advancing year of age. Some modifıable correlates that were related to more than one physical activity outcome were rules restricting rough games inside and usual daily sleep time for boys. For girls, a preference to play inside/draw/do crafts rather than be active, and child constraints, was associated with more than one of the physical activity outcomes. A novel fınding in this study is the counterintuitive association between parental rules restricting rough games inside and boys’ higher physical activity participation levels.Conclusions: Potential strategies for promoting children’s physical activity should seek to influence children’s preference for physical activity and parent rules. Gender-specifıc strategies also may be warranted.