This study examined the association between adverse childhood experiences (ACEs) and suicidal behaviour in a sample of 1726 young men in an Australian youth justice detention population. Nine ACEs, including child abuse and parental risk factors, were examined. Analyses focused on whether ACEs were associated with suicidal ideation and attempts after controlling for other known correlates including substance use, aggression and out-of-home care exposure. Aboriginal and Torres Strait Islander young men were found to have a higher prevalence and a higher average score of ACEs, but differed very little in relation to reported suicidal behaviour. Higher ACEs scores and specific maltreatment types (i.e. physical and sexual abuse) were positively associated with suicidal behaviour. This relationship was attenuated after controlling for established correlates of suicidal behaviour. The findings underscored the importance of understanding ACEs as major risk factors for suicide in youth justice populations and the need for effective prevention measures.