Australia is currently confronting the issue of whether to legalise same-sex marriage. Thus far debate has been conducted with little reference to human rights theory. This article draws on the theories of John Rawls and John Stuart Mill and analyses whether, by confining the right to marry to heterosexual couples, the law infringes the right to privacy and, conversely, whether the legalisation of same-sex marriage would infringe religious rights of those who are unwilling to provide goods and services to same-sex couples. In so doing, the article adopts a comparative approach, drawing on case law from the United States. The article examines the way in which political debate on the issue has been conducted by the major parties in Australia, and concludes that both the Liberal-National coalition and the Labor party have been motivated by a desire to appease the religious right within their ranks, at the expense of human rights principles.