Gay, lesbian, and bisexual youth may experience significant body dissatisfaction. We examined sexual orientation differences in self-perceived weight status and the prevalence of potentially dangerous weight control behaviors in a representative sample of adolescents.Data were obtained from 12,984 youth between 2003 and 2009 over four cycles of the Massachusetts Youth Risk Behavior Survey, a statewide survey of ninth- through 12th-grade students. Self-perceived weight status and past-month unhealthy weight control behaviors (fasting >24 hours, using diet pills, and vomiting or using laxatives) were compared among gay/lesbian, bisexual, or self-identified heterosexual youth with same-sex partners, unsure youth, and exclusively heterosexual youth using logistic regression, adjusting for age and race/ethnicity.Compared with exclusively heterosexual males, heterosexual males with prior same-sex partners and bisexual males were more likely to self-perceive as overweight despite being of healthy weight or underweight (respectively, adjusted odds ratio [AOR], 2.61; 95% confidence interval [CI], 1.68–4.05; and AOR, 2.56; 95% CI, 1.64–4.00). Compared with exclusively heterosexual females, lesbians and bisexual females were more likely to self-perceive as being of healthy weight or underweight despite being overweight or obese (respectively, AOR, 3.17; 95% CI, 1.15–8.71; and AOR, 2.00; 95% CI, 1.20–3.33). Unhealthy weight control behaviors were significantly more prevalent among sexual minority males (32.5%; AOR, 4.38; 95% CI, 3.38–5.67) and females (34.7%; AOR, 2.27; 95% CI, 1.85–2.78) when considered together relative to exclusively heterosexual males (9.7%) and females (18.8%).One third of sexual minority youth engage in hazardous weight control behaviors. Future research should investigate underlying mechanisms and determine whether clinicians should routinely screen for these behaviors.