Purpose: The purpose of this study was to assess trends in alcohol-related disparities between heterosexual and sexual minority adolescents in the United States from 2007 to 2015. Methods: Data were pooled from the 2007, 2009, 2011, 2013, and 2015 Youth Risk Behavior Surveys (N=207,367) to estimate trends, disparities, and changes in disparities of four alcohol-related behaviors (i.e., lifetime alcohol use, early onset use (<13 years of age), past 30-day use, and past 30-day heavy episodic drinking [HED]) among heterosexual youth and three subgroups of sexual minority youth (SMY) (i.e., gay/lesbian, bisexual, and unsure). Models were sex stratified and adjusted for age, race/ethnicity, and state of data collection. Results: The prevalence of all alcohol-related behaviors declined from 2007 to 2015 for heterosexual youth, but not as consistently for SMY. Disparities in alcohol-related behaviors between heterosexual youth and SMY largely remained stable or widened from 2007 to 2015. Disparities in lifetime alcohol use and past 30-day use were larger between heterosexual boys and gay boys in 2015 relative to 2007. Disparities in early onset use and past 30-day HED were also larger between heterosexual girls and lesbian girls in 2015 relative to 2007. The disparity in past 30-day use between heterosexual girls and bisexual girls was smaller in 2015 compared with 2007. Conclusions: Despite overall declines in adolescent alcohol use, alcohol-related disparities between heterosexual youth and SMY persist and, for some SMY, they have widened.