Sexually transmitted infections (STIs) pose a significant threat to the health and well-being of populations worldwide, and to young people in particular. Despite empirical evidence that comprehensive sex education is an important tool for prevention, the legitimacy and content of sex education in schools continue to be challenged by conservative narratives within society. This paper argues that sex education should be re-imagined as a form of civic training for children and recognised as an important corollary to public health efforts aimed at reducing the rate of STIs. The author's claim builds on notions of sexual citizenship, which consider sexuality to be an essential aspect of citizenship and a form of civic engagement. Sexual citizenship can make three important contributions to the advancement of sex education. First, the model can lead to greater acceptance of the idea of sex education by challenging conservative notions about children and sexuality, which are at the root of the classic objections to sex education. Second, it can help shape the content of sex education by eliciting parallels between civic participation and sex education. Finally, by emphasising how sex education can address some of the social phenomena underlying the spread of STIs, the model can be used to facilitate the incorporation of sex education into public health agendas. Although the author uses sex education in Canada as the principal case study, the paradigm may be equally helpful in other countries. (Contains 9 notes.)