Social norms-based interventions have shown promise in reducing drinking behavior and the resulting consequences in young adults. Although most research has focused on young civilians (i.e., college students), some studies have investigated social norms-based interventions with active-duty military and veteran samples. Yet, research has not yet determined how to maximize the effectiveness of social norms-based interventions in this heavy-drinking population. As an initial step toward this goal, the current study utilized a community sample of 1,023 young adult veterans to examine (a) whether veteran perceptions of the drinking behavior of their veteran peers differ from their perceptions of civilian drinking behavior, (b) whether perceptions of specific veteran groups differ from the actual drinking behavior of veterans within those groups, (c) what levels of specificity in reference groups (same-gender civilians, same-branch veterans, same-gender veterans, or same-branch-and-gender veterans) are most strongly associated with veterans’ own drinking, and (d) whether perceptions about others’ attitudes toward drinking also contribute independently of perceived behavioral norms to veteran drinking. Findings indicated that participants perceived that other veterans drank more than civilians and that veteran groups drank more than veterans in the sample actually drank. Veteran-specific perceived behavioral norms were similar in their associations with drinking outcomes, whereas same-gender civilian perceived behavioral norms exhibited little or no associations with drinking. Veteran-specific perceived attitudinal norms exhibited little or no association with drinking behavior after controlling for perceived behavioral norms. These findings can be used to inform the development of social norms interventions for young adult veterans.