Internalized homophobia (IH) is the endorsement of negative attitudes and stereotypes about sexual minority individuals among those who are LGBQ + . However, although IH is associated with suicide ideation, the underlying mechanisms of this association are relatively understudied. To address this limitation, this research investigates Core Self-Evaluation (CSE; one’s fundamental evaluations about themselves, their own abilities, and their own control) and depression as underlying mechanisms associating IH with suicide ideation. CSE comprises four traits: self-esteem, locus of control, emotional stability, and generalized self-efficacy. An online survey was completed by 404 sexual minority adults (Mean_age = 27.42 years, %Female = 51.50, %Male = 30.40, %Trans Female = 3.2, %Trans Male = 5.4). Participants were recruited via Prolific, an online crowdsourcing platform. Four serial mediation analyses examined the direct and indirect effects of IH on suicide ideation via each CSE trait and depression symptoms. Results showed support for the CSE-depression mediated pathway. Self-esteem, emotional stability, and general self-efficacy (but not locus of control) mediated the relationship between IH and suicide ideation via depression symptoms. Across three serial mediations, greater IH was associated with lower (1) self-esteem, (2) emotional stability, and (3) self-efficacy; lower self-esteem, emotional stability, and self-efficacy were associated with greater reported depression symptoms, which were then associated with greater suicide ideation. This research has implications for understanding the underlying mechanisms that associate IH with poor mental health among sexual minority adults. Studying the social and psychological mechanisms can help develop therapeutic interventions that target suicide ideation and promote positive self-evaluations among sexual minority individuals.