This paper examines school and classroom effects on Daily Physical Activity (DPA) policy implementation in classrooms in Ontario, Canada. In 2005 the Ontario Ministry of Education mandated a policy requiring school boards to "ensure that all elementary students, including students with special needs, have a minimum of twenty minutes of sustained MVPA each school day during instructional time". Based on an adaptation of Chaudoir's conceptual framework, this paper contributes to understanding the extent to which school factors (as reported by administrators) and classroom factors (as reported by teachers) are associated with policy implementation fidelity at the classroom level.