Education professionals play a critical role in health education, both as knowledge providers and as role-models. Drawing on the CONSTANCES French cohort (baseline 2012–19) and adjusting for important confounders, we compared education professionals (n = 14 730) with a random sample of non-education sector employees (n = 34 244) on three indicators of high-risk behaviour (at-risk drinking, current smoking, past-year cannabis use) and three indicators of unhealthy lifestyle (low physical activity, poor adherence to nutritional guidelines, overweight/obesity). Among education professionals, we distinguished between teachers (n = 12 820), school principals (n = 372), senior education advisers (n = 189), school health professionals (n = 128) and school service staff (n = 1221). Compared with non-education sector employees with similar demographic and socioeconomic profiles, teachers were less likely to be at-risk drinkers, to smoke, to have used cannabis in the past year and to be overweight/obese. Other non-teaching education professionals were also less involved in high-risk behaviours than non-education employees, but results were more mixed concerning some lifestyle indicators, with certain non-teaching education professional groups showing a higher likelihood of being physically inactive or overweight/obese. In this nationwide French study, our results suggest a window of opportunity to promote school staff health but also indirectly, that of the youth with whom they interact daily. We suggest that school staff should be supported in health matters not only through the provision of health information but also most importantly, through the development of a favourable and supportive environment enabling them to put health knowledge into practice.