BackgroundPublic attitudes to mental illness could influence how the public interact with, provide opportunities for, and help people with mental illness.AimsThis study aims to explore the underlying factors of the Attitudes to Mental Illness questionnaire among the general population in Singapore and the socio-demographic correlates of each factor.MethodsFrom March 2014 to April 2015, a nation-wide cross-sectional survey on mental health literacy with 3,006 participants was conducted in Singapore.ResultsFactor analysis revealed a 4-factor structure for the Attitudes to Mental Illness questionnaire among the Singapore general population, namely social distancing, tolerance/support for community care, social restrictiveness, and prejudice and misconception. Older age, male gender, lower education and socio-economic status were associated with more negative attitudes towards the mentally ill. Chinese showed more negative attitudes than Indians and Malays (except for prejudice and misconception).ConclusionsThere is a need for culture-specific interventions, and the associated factors identified in this study should be considered for future attitude campaigns.