Introduction The risk of contracting COVID-19 is not uniform across occupations. Certain workers, exposed to diseases/infections, interfacing with the public/colleagues, unable to work from home, and without appropriate personal protective equipment are likely to experience higher workplace exposure to SARS-CoV-2. Objective To describe the proportion of workers potentially exposed to coronavirus in each occupation under ‘routine’ working conditions, as well as a baseline socio-demographic profile of these workers in France. Methods We combined two French cross-sectional population-based surveys: ‘Working Conditions’ (CT-2013) and ‘Medical Surveillance of Occupational Risk Exposure’ (Sumer-2017) to quantify ‘exposure to infectious agents’, ‘face-to-face contact with the public’ and ‘working with colleagues’. We then identified the most exposed occupations before the first lockdown and built an exposure matrix. Finally, we described other socio-demographic characteristics (age, sex, occupational group, educational level, income level, origin) of the workers with the highest potential exposure to COVID-19. Results Before the first lockdown, 42% (11 million) of French workers were exposed to at least two COVID-19 occupational exposure factors. While most exposed workers are in the health care sector, other occupations such as social workers, hotel/restaurant employees, army/police officers, firefighters, hairdressers, and teachers also have a high proportion of exposed workers. Middle age participants, females, unskilled employees, those with post-secondary non-tertiary education, those with lower income level, French-born in overseas departments, and descendants of non-European immigrants faced a greater risk of occupational exposure to coronavirus before the first lockdown. Conclusions Our exposure matrix can now be used as an input in ongoing French cohorts to attribute a baseline level of work-related exposure and adjust it based on actual working arrangements during the epidemic. Surveillance of occupational exposure to coronavirus and the socio-demographic characteristics of the workers vulnerable to this virus is key to the implementation of occupation-specific public health response to Covid-19.