Suicide is a global public health issue which has far-reaching impacts on individuals, families, and wider communities. Early intervention is a core pillar of policy on the prevention of suicide related deaths. However, limited mental health literacy, and negative attitudes regarding mental illness amongst the public are a barrier to early intervention. Past research has not explored mental health literacy and attitudes regarding suicide specifically. The aim of the current study was to examine mental health literacy and attitudes towards suicide in adults. 590 adults in Ireland aged 18-80 years (M = 43.24, SD = 12.6) took part in this online cross-sectional study, completing the Mental Health Literacy Scale and The Attitudes Towards Suicide Scale. Experience of suicide deaths was common among participants. Independent t-tests indicated that males had significantly lower levels of mental health literacy and more stigmatising attitudes towards suicide than females. Young adults also had lower ability to recognise mental health difficulties than older adults. Hierarchical Multiple Regressions found that mental health literacy significantly accounted for varied attitudes towards suicide in adults, particularly willingness to communicate about suicide, and beliefs that suicide is preventable. Findings are discussed in the context of informing policy-makers who are promoting early-intervention for suicide prevention.