The provision of formal childcare services holds significant potential benefits in addressing challenges posed by population ageing, labour shortages and welfare dependency. However, existing literature indicates persistent differentials in formal childcare uptake by migration background, with limited understanding of underlying demand-side factors. This study addresses this gap by comprehensively examining demographic, socio-economic, employment-related and attitudinal characteristics as potential explanations for these disparities. Utilising data from the Generations and Gender Survey across seven high-income countries, our findings reveal that whereas differentials for migrants’ descendants are limited and insignificant even without controlling for background variables, the negative differential for migrants disappears almost completely. Socio-economic status and particularly employment potential emerge as a key explanatory factors alongside differential attitudes towards maternal employment, which seem to play a role in some contexts, yet not in others. Cross-country differences in the results are discussed in the face of socio-economic gradients in formal childcare uptake, migrant-native gaps in the labour market and below-demand supply of formal childcare, yet also plead for future research interacting demand- and supply-side factors for a larger set of countries. In conclusion, this study reveals the intricate interplay of demographic, socio-economic and attitudinal factors underlying migrant–native disparities in formal childcare uptake.