Amidst the COVID-19 lockdowns, it became obvious that migrants play a critical role in economic sectors that are essential to the functioning of everyday life. Are they over-represented in these sectors, and how is the use of migrant labour linked to structural factors in the provision of essential services? Using micro data from the EU Labour Force Survey (EU-LFS) 2011-2020 for 17 countries, this paper investigates the extent and the drivers of migrants’ over-representation in key sectors (e.g. health, long-term care, food supply) relative to the rest of the economy. We measure the difference in the probability of working in key sectors for various types of migrants to similar natives across countries of destination. Our results show that in most countries, migrants are over-represented with respect to native-born workers after accounting for individual characteristics. We also provide an overview of the correlation between this residual over-representation and potential structural factors. We find a strong and robust correlation between migrants’ relative employment probability in key sectors and precarious job conditions, the degree of autonomy and flexibility at work, as well as attitudes to migrants, both at the country-level and across sub-national regions.