In 2017, the Australian Government commissioned a national vote on same-sex marriage legislation, which elicited substantial debates dominated by religious voices. We examine the associations between religious identification, importance of religion to one's life and frequency of attendance at religious services and support for same-sex couples in such a unique context. We contribute to knowledge by (i) systematically examining these relationships in a country other than the US (Australia) using high-quality, nationallyrepresentative panel data spanning 2005-2015 (Household, Income and Labour Dynamics in Australia Survey; n=44,794 observations/18,384 individuals), (ii) assessing the degree of intragroup heterogeneity in views towards equal rights, and (iii) considering how religiosity modifies the effects of other socio-structural factors. We find high degrees of between-and within-group heterogeneity in support of equal rights for same-sex couples, and large religiosity gradients. Furthermore, religiosity suppresses the liberalising effects on attitudes of historical time, education, socioeconomic background, and city residence. BACKGROUND Recent debates about recognising same-sex marriage provide a site for the examination of the role of religion in the public sphere. Australia provides a unique opportunity, having recently conducted a national vote to gauge public opinion on same-sex marriage. While the presence of religious voices in public policy debates in Australia have been consistent, the 2017 Australian national ballot on marriage equality emerged as an arena where religious communities actively attempted to dictate what was to happen in the wider society. Religious groups, who in 2016 conducted fewer than 25% of weddings, actively campaigned to limit marriage to heterosexual couples for the whole of society-even though they were (and are) able to privately refuse to marry such couples. This paper offers a discussion of the role of religion in recent debates about same-sex marriage in Australia. Using a large, nationally representative panel study, it provides a detailed analysis of whether and how the views promoted by religious groups resonate with the views reported by individuals who identify with those religions. Specifically, we assess the importance of individual-level variables such as religious identification, religious participation and importance of religion as predictors of support of equal rights for same-sex couples. We make three key contributions to the literature. First, we draw detailed attitude comparisons amongst highly disaggregated religious groups in a new and interesting country context, Australia. In doing so, we question the universality of theories and findings from the US, where the bulk of the research has taken place, and tease out the importance of institutional context (Adamczyk 2017). Second, we discuss and test the degree of intra-group heterogeneity in attitudes to same-sex couples, which we take as a proxy for denominational subcultures (Gay et al. 1996). Third, using ...