During COVID-19 lockdowns it became visible that migrants are often important in sectors that are crucial for the functioning of everyday life. Informed by this experience, this note provides an assessment of the role of foreign-born workers in essential services (referred to as migrant key workers) at regional level for 31 European countries. It examines the share of migrant key workers in regional labour markets, their importance in jobs with different skill requirements, and differences between EU and non-EU migrants. Migrants play a crucial role in health care, where 23% of doctors and 14% of nurses are foreign-born. In cities such as London or Brussels, around half of all doctors and nurses are migrants. Overall, capital regions have the highest share of migrant key workers (20%). Similarly, cities rely more on migrant key workers than other areas, especially in low-skilled occupations where migrants make up 25% of workers.