Gender and, to a lesser extent, sexual identity, are relevant factors in understanding variance in the prevalence, consequences, and treatment of conduct problems. The current study uses thematic analysis to explore how youth with early-onset conduct problems and extensive histories of school-based service use perceive gender and sexuality as impacting their service use experiences. Qualitative analysis of interviews with 41 youth (17-21 years old; 53.7% women) yielded themes pertaining to gender, sexual identity, and discrimination in service use contexts. Identified themes included homophobia in service use and adjacent school contexts, stereotypes around masculinity and femininity as conditioning peer and school staff's behavior, and salience of sexuality across developmental stages and historical timeframes. Results suggest that increased school staff training and school-based interventions be implemented to support gender and sexual diversity, both within services for conduct problems and more broadly in school contexts. In particular, the current findings highlight homophobia as a factor limiting boys' access to mental health services.