The Ontario Ministry of Education (OMOE) implemented the Daily Physical Activity (DPA) policy (OMOE, 2005), which mandates that children receive 20 minutes of sustained moderate to vigorous physical activity (PA) during instructional time daily. The purpose of this thesis was to describe how and to what extent the DPA policy is being implemented, and to generate strategic recommendations to optimize its delivery across Ontario. Two separate studies surveyed teachers (n = 66; Study 1) and parents (n = 172; Study 2) to characterize DPA implementation strategies and fidelity, and to identify associated facilitators, correlates, and barriers. Results indicate that the directives of the DPA policy are not being satisfied by teachers and are not being communicated to parents. Study 3 reviewed the internal and external validity of published PA interventions in children to identify effective strategies for PA behaviour change. Together, findings from the three studies identified modifiable predictors of DPA delivery and family-based support, and informed future research and recommendations.