Lesbian, gay, bisexual, and queer (LGBQ) and female youth report disproportionately high rates of attempted suicide. Previous studies have not addressed the association between sexual orientation, gender, and attempted suicide among adolescent psychiatric inpatients. This study examined LGBQ orientation as a correlate of attempted suicide above and beyond other risk factors (e.g., age, rurality, trauma exposure, psychopathology), and also examined the interaction between gender and sexual orientation with regard to attempted suicide. We conducted a chart review study that included 550 adolescent psychiatric inpatients admitted to a public psychiatric hospital. Adolescents completed standardized intake assessments and self-report measures of sociodemographics, history of attempted suicide, psychopathology, and trauma history. Sexual orientation, gender, and their interaction were evaluated as predictors of attempted suicide using sequential logistic regression. LGBQ youth were more than 3 times more likely (odds ratio [OR] = 3.08) than non-LGBQ peers to have attempted suicide, and female youth were more than twice as likely to have attempted suicide compared with male patients (OR = 2.44). There was not a significant LGBQ orientation by gender interaction. These findings demonstrate the importance of LGBQ orientation and female gender as risk factors for suicidal behavior in a sample of adolescent psychiatric inpatients. Although limited by the self-report and retrospective nature of the data collected, these findings suggest the importance of initial and ongoing assessment of gender, sexual orientation, and suicidality in inpatient youth and the need for additional research to inform effective intervention efforts in this high-risk population.