This self-report study of 404 incarcerated youth found extraordinarily high rates of sexual minority status (SMS; i.e., lesbian/gay or bisexual) among the girls, particularly girls of color. Further analyses of the 107 girls 16 and older found that SMS girls reported being the victims of abuse and engaging in self-harming behaviors more than non-SMS (straight) girls. Structural equation models indicated that regardless of sexual identity, abuse was a risk factor for self-harming. This relationship held for physical or sexual abuse and for abuse by family members or people outside the family. Relative to non-SMS girls, SMS girls demonstrated higher rates of sexual abuse, primarily family sexual abuse, which mediated the relationship between SMS and self-harming.