Introduction. Despite the prominence of shame in stigma theories, its role in explaining population-level disparities in suicidality between the stigmatized and non-stigmatized has not been investigated. Given their pervasive exposure to stigma, sexual minorities might be particularly likely to experience shame and its characteristic outcomes, namely suicidal thoughts, depression, and social anxiety. We hypothesized that shame would mediate the sexual orientation disparity in these outcomes. We also hypothesized that, among the sexual minority sample, there would be a significant indirect effect of shame in the association between past-year family rejection and childhood bullying and these outcomes. Methods. Data come from three annual waves of the Pathways to Longitudinally Understanding Stress (PLUS) study, a longitudinal population-based cohort study among sexual minority and heterosexual young adults in Sweden (baseline n=2,222). We assessed sexual orientation at Wave 1, shame explicitly (via self-report) and implicitly (via a behavioral task) at Wave 2, past-year family rejection and childhood bullying at Wave 2, and suicidal thoughts, depression, and social anxiety using validated scales at Wave 3. Results. Compared to heterosexuals, sexual minorities evidenced higher explicit and implicit shame. Multiple mediation models showed support for significant indirect effects of both measures of shame, indicating that they serve as mediators of the higher levels of suicidal thoughts, depression, and social anxiety among sexual minorities compared to heterosexuals. Only explicit shame had a significant indirect effect in the association between past-year family rejection and suicidal thoughts and between childhood bullying and suicidal thoughts. A significant indirect effect did not exist for internalized stigma, suggesting that it does not serve as a mediator of these associations. Discussion. Results suggest the potential benefit of extending existing stigma theories to consider the role of emotions like shame as characteristic reactions to stigma. This study also highlights the methodological benefit of incorporating innovative measures of psychological experiences, like shame, into population-based studies. Future research is needed to identify whether and how targeted interventions can reduce shame to alleviate population disparities in suicidality, including among sexual minority populations.