Public health is about policy, power, and the public and as such might be thought necessarily political. That does not mean, however, that the place of political analysis and engagement in public health is uncontroversial, and there have been longstanding arguments that to discuss politics sullies the scientific nature of public health. This article, introducing a special issue on political science in public health, argues that rigorous use of middle-range theory can inform our analysis of public health problems and avoid the risks of politicization, excessive abstraction or excessive concreteness. It summarizes key political science concepts discussed in the papers: epistemic communities, interest groups, advocacy coalitions, political parties, institutions, legalism, discourse and the political economy of labour. We hope that the series will provide the public health community with some tools and methods for how to integrate public health knowledge into the sphere of decision making in an appropriate way.