Purpose-To examine the relationship between sexual orientation and past-year reports of bullying victimization and perpetration in a large sample of American youth.Methods-Survey data from 7,559 adolescents aged 14 to 22 who responded to the 2001 wave questionnaire of the Growing Up Today Study were examined cross-sectionally. Multivariable generalized estimating equations regression was performed using the modified Poisson method. We examined associations between sexual orientation and past-year bully victimization and perpetration with heterosexuals as the referent group, stratifying by gender and controlling for age, race/ethnicity, and weight status.Results-Compared to heterosexual males, mostly heterosexual males (risk ratio (RR): 1.45; 95% confidence interval (CI): 1.13, 1.86) and gay males (RR 1.98; CI 1.39, 2.82) were more likely to report being bullied. Similarly, mostly heterosexual females (RR 1.72, 95% CI 1.45, 2.03), bisexual females (RR 1.63, 95% CI 1.14, 2.31), and lesbians (RR 3.36, 95% CI 1.76, 6.41) were more likely to report being bullied than were heterosexual females. Gay males (RR 0.34, 95% CI 0.14, 0.84) were much less likely to report bullying others than were heterosexual males. Mostly heterosexual females (RR 1.70, 95% CI 1.42, 2.04) and bisexual females (RR 2.41, 95% CI 1.80, 3.24) were more likely to report bullying others than heterosexual females. No lesbian participants reported bullying others.Conclusions-There are significant differences in reports of bullying victimization and perpetration between heterosexual and sexual minority youth. Clinicians should inquire about sexual orientation and bullying, and coordinate care for youth who may need additional support.