Research has identified a wide range of factors that influence the health of children and their health as adults. Key among these are early childhood conditions, care, and education, housing security and income security. A number of indicators have been developed to measure the health of children such as the incidences of infant mortality and low birth weight. In international comparisons with other rich countries, Canada ranks poorly. These health outcomes are not inevitable but are shaped by the quality and distribution of a wide range of social determinants. Public policies shape access to and quality of the social determinants of children’s health (SDCH). Because the SDCH are amenable to public policy, it is important to understand public policy and the public policy development process in order to promote policy change. Yet few health practitioners who work with children consider or understand how the public policy development process works. This article examines three models of public policy development: pluralism, policy paradigms, and political economy. It will be argued that of the three models, political economy, with its focus on the role of political ideology and power distribution, provides the most compelling explanation of the public policy development process and provides means to bring about policy change to improve the health of children.