ObjectiveSuicide is the second leading cause of death in Canadian adolescents. The Interpersonal Theory of Suicide attempts to explain suicide etiology and proposes that feelings of perceived burdensomeness or thwarted belongingness lead to suicide ideation, but this has not been extensively studied in adolescents. This study aimed to use the Interpersonal Theory of Suicide to examine factors that may be associated with suicide ideation in adolescents. The factors of interest were school connectedness, perceived availability of support, self-esteem, feelings of worthlessness, feelings of hopelessness, bullying and cyberbullying victimization, substance use, and social media use.MethodsData were from the 2017 Ontario Student Drug Use and Health Survey, a survey of 7th to 12th graders enrolled in a publicly funded school in Ontario. Weighted multivariate logistic regression of suicide ideation on all exposure variables was conducted.Results13.6% of students in the sample endorsed having suicidal ideation in the preceding 12 months. Not knowing where to turn to for support, feeling worthless, endorsing low self-esteem, being bullied, and using cannabis were each associated with greater odds of suicide ideation. Feeling hopeless, social media use, using alcohol and tobacco,and being cyberbullied were not associated with suicide ideation in the weighted multivariate logistic regression model.ConclusionsThis study is consistent with the Interpersonal Theory of Suicide as low self-esteem and feelings of worthlessness, two indicators of perceived burdensomeness, and not knowing where to turn to for support, an indicator of thwarted belongingness, were associated with greater odds of suicide ideation. These findings can help guide interventions aimed at reducing the burden of suicidality during adolescence and demonstrate the need to provide accessible mental health support for youth.