Introduction: Suicide is a leading cause of death among young people (aged 15-24 years), and as such, identifying targets for early intervention is essential to reducing this risk. Using baseline data from a school-based universal suicide prevention trial, we investigate factors associated with different types of suicidal ideation in secondary school students with implications for youth suicide preventive efforts. Methods: A self-report questionnaire was administered to students aged 13-16 years (Year 9) before program delivery in four regions across New South Wales, Australia (N = 556). Multinomial logistic regression was used to identify correlates of suicidal ideation type (passive vs. active). Results: Approximately half the total sample reported recent suicidal ideation (51.6% in the previous two weeks), which included almost one-third reporting active suicidal ideation (32.2% seriously considered suicide or made plans). Participants that were significantly more likely to report active suicidal ideation compared to passive suicidal ideation identified as female (OR = 1.91, 95% CI = 1.02-3.59), Indigenous (OR = 0.21, 95% CI = 0.05-0.80), as sexual minorities (OR = 0.36, 95% CI = 0.13-0.97), and had greater depression severity (OR = 1.11, 95% CI = 1.04-1.19). Conclusions: Suicidal thoughts are prevalent among young people. Universal and indicated preventive interventions that address depression, as well as bullying and discrimination of minority groups would benefit all young people, particularly those more vulnerable to severe suicidal ideation and suicide attempts.HighlightsActive suicidal ideation (SI) was reported by 32.2% of our student sample aged 13-16 years.Active SI is linked to sex (female), Indigeneity status, sexual minority status, and greater depression severity.Improved bullying and discrimination policy within schools, and well-being programs targeting depression and promoting help-seeking, would benefit youth.