BACKGROUND:The proportion of Australians who choose not to drink alcohol has increased in recent years; yet, non-drinkers report experiences of stigma and judgement from peers for this choice. This study aimed to explore the attitudes that exist towards non-drinkers and examine what drives this stigma. METHOD:Thematic analysis of four focus groups was undertaken, comprising 37 drinking and non-drinking Australian adults. RESULTS:Three themes were identified that elucidate the stigma, with non-drinkers being perceived as a: (1) threat to fun, a judgemental 'sober eye' disrupting the desired hedonistic environment created by alcohol, (2) threat to connection, described as difficult to initiate and maintain a social connection with and (3) threat to self, with the presence of a non-drinker described by drinkers as encouraging an unwanted reflection on the problematic aspects of their own drinking. Participant responses also suggested that the gender of the non-drinker influenced these perceptions. CONCLUSION:Through the lens of Integrated Threat Theory, this study proposes that the stigma experienced by non-drinkers may be understood as a response to threats non-drinkers are perceived to pose to drinkers' group values (e.g. hedonism) and self-esteem. This study offers new direction for health promotion efforts to challenge negative perceptions of non-drinkers.