This Element explores the association between political democracy and population health. It reviews the rise of scholarly interest in the association, evaluates alternative indicators of democracy and population health, assesses how particular dimensions of democracy have affected population health, and explores how population health has affected democracy. It finds that democracy - optimally defined as free, fair, inclusive, and decisive elections plus basic rights - is usually, but not invariably, beneficial for population health, even after good governance is taken into account. It argues that research on democracy and population health should take measurement challenges seriously; recognize that many aspects of democracy, not just competitive elections, can affect population health; acknowledge that democracy's impact on population health will be large or small, and beneficial or harmful, depending on circumstances; and identify the relevant circumstances by combining the quantitative analysis of many cases with the qualitative study of a few cases.