Background: Fertility can be conceptualized as a population-level health outcome. Globally, total fertility rates (TFRs) have persistently fallen below replacement level, signaling a profound transformation in reproductive health behaviors with far-reaching implications for population health and societal well-being. Although economic development, educational expansion, gender equality, and demographic transition are well-established drivers of fertility decline, the role of internet diffusion as a contextual, health-relevant exposure remains insufficiently examined.

Objective: Addressing this gap, the present study investigates whether national levels of internet diffusion are associated with TFRs beyond demographic, economic, and gender-related determinants.

Methods: Using three publicly available cross-national datasets, we conducted hierarchical regression analyses across 71 nations to examine the association between TFR and internet diffusion, followed by subgroup analyses stratified by development status.

Results: Internet diffusion was a significant cross-national correlate of lower TFRs after controlling for economic development, population characteristics, and gender equality indicators. Subgroup analyses revealed a significant negative association between internet diffusion and fertility rates in developing nations, whereas the internet–fertility association was positive but not statistically significant in developed nations.

Conclusion: These findings extend fertility research by identifying internet diffusion as a salient macro-level correlate of reproductive outcomes. More broadly, the study adds a digital dimension to current fertility and reproductive health research, which has typically emphasized economic, demographic, and policy determinants over digital environments. Policies and public health research aimed at promoting reproductive well-being in the digital era should explicitly consider the influence of digital environments on reproductive decision-making.