Background: Tobacco, alcohol, and illicit drug use among lesbian, gay, and bisexual (LGB) high school students as well as related environment and school-level risk and protective factors were examined. Methods: Data was acquired from the 2015 CDC's Youth Behavior Risk Survey for Kentucky (N = 2577). Prevalence of substance use was calculated for all high school respondents by reported sexual orientation. Multivariate analyses estimated the relationship between school and environmental-level factors (eg, having an adult to talk to) and tobacco, alcohol, and illicit drug use via logistic regressions. Sexual orientation, gender, age, and race/ethnicity were covariates. Results: LGB students used tobacco, alcohol, and illicit drugs more frequently than their heterosexual counterparts. More LGB teens report facing school risk factors (eg, 37% LGB vs 20% heterosexual bullied at school, p = 0.001; 17% LGB vs 5% heterosexual ever threatened or injured at school, p < 0.001; 13% LGB vs 7% heterosexual involved in a school fight, p = 0.001). Adjusting for school related risk factors, having an adult to talk to was associated with a reduced likelihood of daily smoking (adjusted odds ratio [aOR]: 0.43; 95% confidence interval [CI]: 0.26-0.73), past 30-day alcohol use (aOR: 0.71; 95% CI: 0.50-0.95), and ever marijuana use (aOR: 0.71; 95% CI: 0.50-1.00). Conclusion: Innovative strategies are needed to create safe, supportive school environments. These strategies are particularly needed in predominately rural states like Kentucky.