Background Self-harm and suicidality are major public health concerns and are notably higher among the Indigenous population in Australia. We aimed to identify factors protecting Indigenous adolescents from self-harm and/or suicidality at the individual and community level.

Methods Secondary data analysis was conducted using data from the Longitudinal Study of Indigenous Children. This study included those of adolescents aged 13–15yr with complete data for self-reported self-harm and/or suicidality (from wave 11) and predictor variables (from wave 10 and 11), and multilevel logistic models were employed.

Results We included 365 adolescents (mean age 14.04), 8.2% (n=30) of whom reported intentional self-harm in the past-12 months; 4.1% (n=15) reported suicidality. Multilevel analysis revealed being male, having strong family cohesion and living in urban areas was protective against self-harm and suicidality (p<0.05 for all). We found that having a strong Indigenous identity did not protect against self-harm and/or suicidality. However, low SDQ scores (collected 1yr prior to outcome(s)) were found to be protective against self-harm/suicidality (p<0.05), and further underscore SDQ’s usefulness in identifying children and youth who may need more social, behavioural, and emotional support.

Conclusions Adolescents are at a critical juncture in their path to adulthood, and this identification of protective factors among Indigenous adolescents may inform future initiatives.

Learning outcomes The significance of Indigenous identity should be advocated to improve self-harm/suicidality among Australian Indigenous adolescents. Future strategies also need to consider the higher risks among females, those living in rural areas, with high SDQ scores and households with poor cohesion.