Objective: To determine the prevalence and sociodemographic profiles of mental morbidity and multimorbidity. Methods: A descriptive analysis was performed with data from 25,269 women and 8,389 men from the French NutriNet-Santé general-population cohort. Participants were split into 8 groups: 1. No mental morbidity; 2. Pure anxiety; 3. Pure insomnia; 4. Pure eating disorders (ED); 5. Comorbid anxiety and insomnia; 6. Comorbid anxiety and ED; 7. Comorbid insomnia and ED; 8. Multimorbid anxiety, insomnia, and ED. Data were weighted using the 2016 French Census and analyzed with Chi 2 tests. Results: 40.6% of the participants had ≥1 mental disorder; 2.3% had all 3 disorders. Most pure and comorbid disorders were more common in women than in men. The multimorbidity group had the largest proportions of men who were overweight (52.1%) and current smokers (23.2%). Men with insomnia and ED were the most likely to have obesity (45.8%) and low physical activity (44.3%). Women with ≥2 disorders were the most likely to be current smokers. Conclusion:The findings could inform research, prevention, and public health guidelines for multimorbidity.