Child care, conceptualized as one area of social policy, is a good example of a population health intervention (PHI) that operates outside of the health sector. Exploration of child care as a PHI could help to clarify the scope of the PHI field, and contribute to a credible base from which to advocate for PHIs, yet such exploration is not yet prominent in the population health research literature. The purpose of this paper is to consider child care through the lens of PHI, and in particular, to consider whether a strong case can be made for a universal approach to child care in Canada and perhaps other liberal welfare regimes where targeted approaches are more commonly accepted. We first examine the peer-reviewed evidence on the impact of universal and targeted child care for later outcomes. We then interrogate other issues that are pertinent to making a strong case for universal child care in Canada as one example of a liberal regime; namely, (1) limitations and challenges of research on the impact of universal child care; (2) the intuitive appeal of targeting; (3) the fundamental differences between targeted and universal approaches; and (4) the values inherent in judgments about the equity of universal interventions. Notably, some of these issues do not lend themselves to empirical resolution, which raises interesting questions about the acceptable balance of ideology and empiricism in population health. (author abstract)