Abstract Background Mosquito-borne diseases (MBD) are increasing and expanding their range throughout metropolitan France. Promoting individual protective behaviour is imperative, but research on its determinants is limited to southern regions. This study examines factors influencing MBD protective behaviour in the metropolitan French population. Methods 2,087 subjects responded to a self-administered online questionnaire in November 2023. The analysis plan was pre-registered. We fitted two mixed effects models to estimate the frequency and count of protective behaviours across sociodemographic groups and to identify which factors predict protective behaviour. Results Frequency of protective behaviour is significantly positively associated with getting bitten by mosquitoes often (β = 3.39; 95% CI: 3.10, 3.69) and sometimes (β = 1.54; 95% CI: 1.31, 1.76) compared to almost never, perceived MBD threat (β = 0.11; 95% CI: 0.06, 0.15), and having financial difficulties (β = 0.23; 95% CI: 0.02, 0.43). Count of protective behaviours is associated with getting bitten by mosquitoes often (β = 0.39; 95% CI: 0.30, 0.49) and sometimes (β = 0.14; 95% CI: 0.05, 0.23), perceived MBD threat (β = 0.02; 95% CI: 0.00, 0.03), MBD knowledge (β = 0.06; 95% CI: 0.04, 0.08), and having a chronic disease (β = 0.08; 95% CI: 0.02, 0.14). Models were adjusted for place of residence, education, and age. No associations were found between sex, having experienced an MBD, or confidence in public authorities to manage health crises. Conclusions This study provides the first insights into MBD protective behaviour and its associated factors considering all metropolitan French regions. Our results highlight several factors which may inform MBD prevention communication and policies focused on increasing individual protective behaviour. Key messages • People often bitten by mosquitoes are more likely to engage in more frequent and a higher number of mosquito-borne disease protective behaviour than people almost never bitten by mosquitoes. • Higher perceived mosquito-borne diseases threat is associated with more frequent and a higher number of mosquito-borne disease protective behaviour.