Background Research on susceptibility to alcohol use disorder within the attention deficit/hyperactivity disorder (ADHD) population has begun to expand examination of putative moderators and mediators in order to develop effective treatments. Specific dysregulated emotions have been separately associated with ADHD and with alcohol use difficulties. The current study is the first to conjointly study these variables by testing anger‐irritability as a mediator of ADHD risk for adolescent alcohol use. Methods Frequency of binge drinking, drunkenness, and alcohol problems were examined for 142 children with ADHD followed into adolescence and compared to 100 demographically similar youth without ADHD. Parent‐rated anger‐irritability was tested as a mediator. Behavioral and cognitive coping skills, which are key clinical treatment targets, were studied as moderators of these associations. Results Childhood ADHD was positively associated with anger‐irritability and the drinking outcomes in adolescence. Anger‐irritability mediated the association between ADHD and alcohol use problems, but not binge drinking or drunkenness. Behavioral and cognitive, but not avoidant, coping played a moderating role, but only of the association between childhood ADHD and anger‐irritability. Conclusions Active coping strategies by adolescents with ADHD may reduce the vulnerability to alcohol problems through a reduction of negative emotions. Future research on additional mediators and treatments that target these skills is encouraged.