Throughout the latter half of the 20th century, cross-national primary education has improved substantially, even when considering remaining inequalities between nations. In order to further tease apart the complex mechanisms that have facilitated this growth, the present study posits that global reductions in health inequality (defined as a country’s distribution of age at death) has played a key role in increasing primary school enrollment. Health inequality is theorized to negatively affect primary school enrollment by acting as a collective proxy of distinct phenomena within a population, such as prevalence of mortality, prevalence of poor childhood health, and prevalence of parental health shocks. To test the relationship between health inequality and primary school enrollment, this study employed a cross-national unbalanced panel dataset of 806 observations across 142 nations from 1970 to 2015. Across random and fixed effects models as well as sensitivity analyses, higher levels of health inequality were significantly associated with lower primary school enrollment. Therefore, evidence suggests that improvements in cross-national health equality contributed in part to the substantial increase in global access to primary education.