Objective: This study aimed to investigate the prevalence and correlates of food insufficiency and its association with mental disorders and adverse childhood experiences (ACE) in Singapore. Design: This analysis utilised data from the Singapore Mental Health Study (SMHS 2016). Setting: SMHS 2016 was a population-based, psychiatric epidemiological study conducted among Singapore residents. Participants: Interviews were conducted with 6126 respondents. Respondents were included if they were aged 18 years and above, Singapore citizens or permanent residents and able to speak in English, Chinese or Malay. Results: The prevalence of food insufficiency was 2·0 % (95 % CI (1·6, 2·5)) among adult Singapore residents. Relative to respondents who did not endorse any ACE, those with ACE (OR: 2·9, 95 % CI (1·2, 6·6)) had higher odds of food insufficiency. In addition, there were significant associations between lifetime mental disorders and food insufficiency. Bipolar disorder (OR: 2·7, 95 % CI (1·2, 6·0)), generalised anxiety disorder (OR: 4·5, 95 % CI (1·5, 13·5)) and suicidal behaviour (OR: 2·37, 95 % CI (1·04, 5·41)) were shown to be significantly associated with higher odds of food insufficiency. Conclusions: The prevalence of food insufficiency is low in Singapore. However, this study identifies a vulnerable group of food-insufficient adults that is significantly associated with mental disorders, including suicidality. Government-funded food assistance programmes and multi-agency efforts to deal with the social determinants of food insufficiency, such as income sufficiency and early detection and intervention of mental distress, are key to ensuring a sustainable and equitable food system.